Want to give a shout out to dutch_122 - not sure if allowed within the rules of this forum? - for helping with the following first time DONE trip that we are part way through, highly recommend him:

We had a bunch of trips for 2026. We are based in NYC, and had a trip to Australia / NZ from Europe before going back to NYC, then some West Coast plans, then a trip to Kenya / Seychelles. Realised that a DONE5 would allow us to string them all together. Managed to avoid a lot of YQ/YR fees by plating on QR and avoiding international BA/IB/AA flight numbers as much as possible (but still had to for various reasons see below)

Route ended up being: OSL - xDOH (QR) - MEL (QR) - CNS (QF) - SYD (QF) - AKL (QF) - JFK (QF) - LAX (AA) - ANC (AS) - ORD (AS) - xLHR (AY on BA) - NBO (BA); SEZ (QR)- xDOH (QR) - LHR (QR) - TOS (BA).
Price ended up being around 8k USD pp IIRC (proactively changed flights to avoid DOH on the way to NBO which bumped up the YQ/YR because of the BA flight LHR-NBO, the total hotel / safari no-show fees in Kenya are an uninsurable 20k, so not taking any risks getting there on QR.)
Plating on AA etc. was around 9k USD. Fully aware other optimisations available, but priority was securing trips in Business to places we wanted to visit, not just minimising the YQ/YR fees.

Learned that sadly even AA are now rejecting the multiple stopovers inside North America, so couldn't stopover in JFK multiple times despite several HUCA attempts etc.
Bizarre new internal rule...
QR are also still learning the DONE rules for sure... lots of fun with them discovering which state Chicago is in (hint: not West Coast or East Coast ones)

Decent Tier Points for anyone still crediting to BA due to the QR/AY segments. Could have optimised for more Tier Points ofc (more AY / QR / JL flights), but not the priority.