Thanks.

Apparently, I should have gone back further in the thread. Oh well, next time.

Are you suggesting split each of us onto separate PNRs, or (as I had been thinking) just my wife? If my son and I are on the same PNR, can one of us get CPU'd, but not the other? If him and I are on separate PNRs, will he be eligible for CPU at all? (I thought I knew the ins and outs of CPUs but apparently not when others are on the same ticket.)

Do I do the split now? Wait until the fare bucket opens? Do it at check-in?

So straightforward problem. 1K plus GM on single PNR with 2 GPUs applied on INTL flight. If we stay together, we need the system to open R2 or we don't clear, no matter if our fare class or time requested is above a single passenger. The obvious answer is split the PNR. So the GM now carries a 1K priority on the upgrade waitlist and we clear one at a time, presumably back to back as no one should slide between us because our request time is identical (unless they purchase a higher fare and apply a GPU between sweeps).

But what does the GM lose? I understand the IRROPs issues. Does she also lose 1K check bag privileges? Boarding class privileges? E+ privileges? Where does the GM carry 1K and where does she not? On an INTL flight, are there really any downsides big enough to not split the PNR?

If you son/you are on same PNR, both can be CPU'd.
If you split him beforehand, he will not be CPU'd.
Let the system split you, if you have not been upgraded already at check-in. This way, if you have been upgraded already, you keep everything properly for the return.

Technically, nothing is lost. Practically speaking, the GM will no longer automatically receive the 1K baggage allowance, E+ seating, or BG1. However, all of these can be overridden by an agent, who will happily do so when looking at the history of the reservation.

Really, the only loss is increased hassle to get any of those things done.

Not quite true. GM loses 1k priority on the waitlist if PNR is split

Need to add more.
On the leg split, they may drop to the bottom of the elites status group.
But on a future flight, such as a return, yes they are fully unlinked.

Recent report on 2 elites traveling with 2 grands on an expensive Transatlantic. We both should have been entitled to priority seating and possible upgrades for our companion kids, but in order to accomplish this I had t split us out into 4 separate PNRs and spend an hour on the phone with an agent explaining why this was a good idea and getting everyone straight. This did result in priority seating on the outbound, but nothing on the return. Fortunately, they were not seated far away on an overnight flight....
Most remarkably, I was then upgraded when I didn't even think I was eligible for International upgrades.
I think I got everyone back on the companion upgrade list for the domestic portion, but by then everything was gone.

A reminder that the topic was instrument supported upgrades split before check in, not CPU. As such, please clarify if you still think my post was off.

My understanding is a supported upgrade when split will maintain the original elite's status but may fall to the bottom of the status window. But this is an area of fuzzy understanding and there have been some conflicting reports if it maintains the fare class priority -- but no doubt the status is maintained on the segments after splitting.

I think there is some sort of distinction between "split immediately prior to check-in" and "split during check-in". Flying LHR-[US], since I don't hold a US passport, I check in with an agent; when I'm with a companion and we're both WLd, so a split is going to happen, and the split happens ex-LHR, my companion reverts to BG4 rather than BG1 and gets no precheck, which suggests the system saw the companion as split before check-in begun.

By contrast, flying US-anywhere else, when the res is split my companions retain BG1 and precheck, which suggests the system "remembers"/inherits my identity/status during the split.

No idea what a human agent is doing differently than an app, but there does seem to be some sort of distinction there.

That being said, as a first-hand data point when an agent split the PNR to check us in, we experienced what you say above (BG3 on the Y segments) however she was alternately above and below me on the visible upgrade list on multiple downline segments (how exactly this is possible is beyond me).

I'm pretty sure that as long as the instrument is applied before the PNR is split, the companion retains both status and fare class priority. This is for instrument upgrades only - CPUs go to bottom of elite tier.

This is the real question and it sounds like maybe conflicting experiences. What this boils down to is what is more likely to get 2 seats upgraded using a GPU? Staying together or splitting? If the GM loses 1K waitlist priority, then she is never going to get upgraded if I split. If she maintains it though, then it would seems more likely we will upgrade sequentially as two single seats rather than requiring R2. And whatever she loses in BG, baggage, etc. can be fixed by an agent.

And does splitting impact the outbound differently from the return?

Given the uncertainty on this (thanks for trying, everyone), it sounds too risky to split and then watch her fall to the bottom of the list on one or both directions.

If split on the outbound, it does appear the non-status individual loses all inherited priority benefits. At check-in, if with UA, you can "recover" the bag allowance waiver. If E+ seat assignment is lost (such as in a plane swap), a call should be able to restore.
Since they can board/security (but not PreCheck) with you, no problems there.

But the upgrade priority is lost, GA may be able to restore.

I have a question for the loyal UA elites here:

My wife and I have a flight back from Buenos Aires to Houston on Nov 11 (2.5 weeks from now). I am a 1K member, she is a General Member. We booked our ticket a LONG time ago in April and applied our 2 GPUs (under my account to leverage the 1K status). I have spoken to 1K desk, there are only 24/50 seats in business that are booked as of today (10/23).

My concern is that I've been checking the same flight in the near term, and R availability does not seem to open up very frequently before 24-48 hours. So my question to the group is, at 24 hours, if not confirmed, should I check us in on the mobile app and deal with the dreaded "PNR Split" (which I admit I still don't understand), or should I wait to check-in until 2-3 hours before at the airport? Is there any benefit to doing one over the other?

Any guidance would be greatly appreciated.

PG

What's your priority, getting the upgrade, or staying together?

If the priority is getting the upgrade, check-in at the first opportunity. Especially if you're on a W fare.