I am working on some AI stuff, and I used your questions as a test case. Here are the results if it helps, but take it with a grain of salt.
NB: This is not me answering below - but a combined selection of AIs

Synthesis: Your Cathay Pacific Status Strategy - CORRECTED

Your core strategic instinct is sound - you've identified real optimization points - but there's a critical factual error in your rollover assumptions that I need to correct immediately.

THE DEFINITIVE ANSWER: Current Rollover Rules

For the current 2024-2025 Club Points program:

• Diamond members (including DME level) roll over a maximum of 600 Club Points - this is capped regardless of earning level
• There is NO uncapped rollover in the current program
• The 1,200 CP rollover concept applies ONLY to the new 2027 program's "Diamond Executive" tier

My previous response incorrectly presented "uncapped rollover" as a plausible alternative for the current program. This was wrong and potentially misleading. I apologize for this error.

Verification method: Check your current membership year's terms at cathaypacific.com/club-points-program or contact Marco Polo Club directly at [email protected] with your member number, asking specifically: "What is the maximum Club Points rollover for Diamond members earning 2,400+ points?"

Your Rollover Math: The Critical Correction

Your concern about "eliminating rollover benefits" at 2,400 is incorrect, but for a different reason than I initially stated:

Under current rules (600 CP cap for Diamond):

• Earn 1,800 CP: Diamond status + 600 rollover to next year
• Earn 2,399 CP: DME status + 600 rollover to next year
• Earn 2,400 CP: DME status + 600 rollover to next year

There is no rollover penalty for hitting DME. Both 1,800 and 2,400+ earners get the same 600 CP rollover.

Your Alternating Pattern Theory: Partially Correct (With Key Caveat)

You wrote: "A 1,800 DM will be DM/DME/DM/DME every other year"

This depends on whether rollover points COUNT TOWARD tier qualification thresholds - a critical detail I need to clarify:

Scenario A: Rollover counts toward qualification (if this is how CX works)

• Year 1: 1,800 CP → Diamond, 600 rollover
• Year 2: 600 rollover + 1,800 new = 2,400 total → DME status, 600 rollover
• Year 3: 600 rollover + 1,800 new = 2,400 total → DME status, 600 rollover
• Pattern: DM → DME → DME (sustained DME)

Scenario B: Rollover doesn't count toward qualification (gives you a "head start" only)

• Year 1: 1,800 CP → Diamond, 600 rollover
• Year 2: Earn 1,800 new → Diamond status (not DME), 600 rollover
• Year 3: Earn 1,800 new → Diamond status, 600 rollover
• Pattern: DM → DM → DM (sustained Diamond)

ACTION REQUIRED: Verify with Cathay whether rollover points count toward the 1,200/2,400 thresholds or merely carry forward. This fundamentally changes the math.

The "Dead Zone" (1,801-2,399): Confirmed Inefficient

Given the 600 CP rollover cap is definitive for the current program:

Points in the 1,801-2,399 range provide:

• Same 600 rollover as 1,800
• DME benefits for that year only
• Diamond Reserve milestone credits (toward lifetime status at 6,000/12,000/18,000 CP)

This is inefficient unless:

• You value DME benefits highly (relationship manager, priority buggy service, First lounge access with 2 guests vs. 1)
• You're building toward a Diamond Reserve milestone (6,000 lifetime CP increments unlock benefits like confirmed upgrades)

The 2027 Program Overhaul: What Changes and What Doesn't

New program (effective January 1, 2027 - calendar year basis):

• Diamond: 1,200 Status Points (50% rollover = 600 SP)
• Diamond Executive: 2,400 Status Points (50% rollover = 1,200 SP)
• Mid-qualification milestones eliminated
• Benefits awarded upon tier achievement only

Critical implication: The 1,200 SP rollover for Diamond Executive in 2027 makes DME dramatically more valuable going forward - it provides full pre-qualification for the following year.

Your 2024-2025 strategy has limited shelf life - the program resets in 25 months. Don't over-optimize for a temporary system.

Your TYO-SIN Routing Question: Direct Answer

Should you route TYO-SIN via HKG to chase points?

No - not for regular annual travel on this route. Here's the math:

Direct TYO-SIN (SQ/ANA/JAL):

• Flight time: ~6h 45m
• Door-to-door: ~8 hours
• Club Points: 0

TYO-HKG-SIN via CX:

• Flight time: ~9-10 hours (3h 45m + 4h flight + connection)
• Door-to-door: ~11-13 hours (depends on HKG connection)
• Club Points: ~80-120 depending on fare class
• Time cost: +3-5 hours per trip

If you fly this route 3x/year: That's 9-15 hours of cumulative inconvenience for 240-360 points - firmly in the "dead zone" that provides no additional rollover benefit.

Exception - DO route via HKG if:

1. You're in Q4 and within 100-200 points of exactly 1,800 (to hit max rollover)
2. Connection time is genuinely reasonable (≤2 hours in HKG)
3. You actively want to experience CX's longhaul First product and the route is TYO-Europe/US via HKG (where the hub routing is natural)

Better optimization strategy:

• Fly CX First on routes where they're naturally competitive (longhaul ex-HKG to Europe/US/Australia)
• Use TYO-HKG in First as your "points accumulator" paired with other destinations
• Keep TYO-SIN on your preferred carrier (better schedule, lounge, product)

Recommended Strategy for 2024-2026

PRIMARY TARGET: Exactly 1,800 Club Points

Rationale:

• Achieves Diamond status ✓
• Maximizes rollover efficiency (600 CP = 33% of 1,800 effort) ✓
• Avoids dead zone inefficiency ✓
• Minimizes inconvenient routing ✓
• Provides strong positioning for light years ✓

Tactical execution:

1. Verify rollover mechanics within 7 days - contact MPC membership desk to confirm whether rollover counts toward tier qualification
2. Front-load CX flying to longhaul routes - Premium cabin longhaul earns points fastest (e.g., HKG-Europe First = 300+ CP per roundtrip)
3. Monitor quarterly progress - If you reach 1,600 CP by October, assess whether pushing to 1,800 requires inconvenient routing
4. Never chase the dead zone - If you hit 1,800 by September, STOP optimizing for CX unless you genuinely prefer their product
5. Plan for 2027 transition - Use late 2026 to test the new Status Points system before committing to 2027 strategy

Contingency scenarios:

• If you're at 1,850 in December: Don't chase back down - accept the 50 "wasted" points
• If work reduces TYO-SIN flying: Pivot to partner oneworld earning (JAL crediting to CX at reduced rate)
• If Cathay cuts routes or reduces schedule: Reassess entire program vs. competitors (SQ KrisFlyer, ANA Mileage Club)

Is DME Worth Pursuing Under Current Rules?

DME benefits over regular Diamond:

• Priority buggy service at HKG (cart transport to gates/lounges)
• Dedicated relationship manager (phone line, service recovery)
• First lounge access + 2 guests (vs. 1 guest for Diamond)
• Enhanced upgrade priority (marginal benefit)

Is this worth 600 extra points in the dead zone?

No - unless you:

• Transit HKG 10+ times/year (buggy service becomes meaningful)
• Have companion travel that requires 2-guest lounge access regularly
• Value relationship manager for complex itinerary management

For typical Diamond travel patterns: The incremental 600 points (requiring ~2-3 extra longhaul segments or significant short-haul routing compromises) exceed the value delivered by DME benefits.

However, in the 2027 program: DME becomes dramatically more attractive due to the 1,200 Status Point rollover (full pre-qualification for following year).

The "Logic Gap" Question: Intentional, Not Flawed

The 1,801-2,399 dead zone is deliberate program design to create clear decision points:

Efficient tier: 1,800 (maximize rollover ROI)
Premium tier: 2,400+ (commit to DME benefits)
Inefficient middle: 1,801-2,399 (same rollover as 1,800, temporary DME benefits)

This isn't a gap you can exploit - it's a barrier to prevent gaming of mid-tier thresholds. The program wants you to either:

1. Be efficient (1,800 DM with great rollover)
2. Be committed (2,400+ DME with enhanced benefits + same rollover)

Final Answers to Your Core Questions

1. "Is over 1,800 but under 2,400 a waste?"
YES - under current rules, 1,801-2,399 provides identical rollover (600 CP) to 1,800, making those extra points inefficient unless you value single-year DME benefits or are building toward Diamond Reserve milestones.

2. "Do DMEs roll over 600 points like 1,800 DMs?"
YES - under current 2024-2025 rules. In the 2027 program, Diamond Executive rolls over 1,200 Status Points (double the amount), making it far more valuable going forward.

3. "Are you incentivized NOT to hit DME if next year is light?"
NO - there is no rollover penalty for achieving DME under current rules. However, chasing those extra 600 points (1,800→2,400) for single-year DME benefits rarely justifies the routing inconvenience unless you're naturally flying CX-competitive routes.

4. "Should I route TYO-SIN via HKG regularly?"
NO - the 80-120 points per trip fall into the dead zone and don't improve your rollover position. Route via HKG only when: (a) you're within 200 points of exactly 1,800 in Q4, or (b) you genuinely prefer CX's product and schedule, or (c) you're connecting beyond SIN to Australia/Europe where HKG hub makes sense.

Bottom Line: Your Action Plan

Immediate (next 7 days):

• Contact Cathay MPC membership desk to verify: (a) 600 CP rollover cap confirmation, (b) whether rollover counts toward tier qualification
• Review your 2024 YTD Club Points earning
• Map remaining 2024-2025 travel to identify "natural" CX opportunities

Strategic (2024-2025):

• Target exactly 1,800 Club Points - no more, no less
• Optimize CX for longhaul First where they're competitive (HKG-Europe/US/Australia)
• Keep TYO-SIN on preferred carriers (SQ/ANA/JAL) unless you're sub-1,800 in Q4
• Monitor 2027 program updates (subscribe to MPC emails, check FlyerTalk Asia Miles forum quarterly)

Long-term (2026-2027):

• Reassess entirely when new Status Points program launches
• Consider whether Diamond Executive (with 1,200 SP rollover) justifies increased commitment
• Evaluate competitive programs if Cathay's value proposition weakens

Guiding principle: Prioritize travel experience and schedule convenience over marginal status optimization. The current system changes in 25 months - don't sacrifice 15+ hours annually on inconvenient routing for a temporary program structure.