Hi,
Would this setup work - OnePlus watch 2/2r for NFC payments - NFC payments are the only reason I haven't moved over?

I am pretty sure that you can do NFC payments through Smart Watches on GrapheneOS without issue. I'd love if they brought GrapheneOS to OnePlus but it doesn't meet the requirements unfortunately.

How about a payment ring from, e.g., Pagopace, Tapster, cnick, McLear, ...?