Ok, I'm going to do it!! See if it all works...most popular carriers should work fine with dual SIM. but some use proprietary carrier profiles that make it difficult to work in AOSP without specific google services. this is rare but does happen. if you're on the fence maybe ask in the matrix room regarding your setup and see if somebody else with similar setup has it working.
GPay won't work (last time I checked a few weeks ago) it's sort of like Android Auto and Google Games.... they require google services that aren't yet fully supported (rightly so) for them to work correctly.
it sounds like you use a ton of apps for work. most should work but it's not guaranteed. sometimes it's best to grab a used pixel 3 for a hundred bucks or something (if its possible), and test out your apps. in your case I would try using a separate phone for work but that's just my opinion. but even buying a phone with a good return policy, and installing GOS and all your apps - to ensure they work, is what I would recommend (although that's sometimes hard to do in some countries).
to check if your apps work, you can look on here: plexus.techlore.tech
although that doesn't tell the whole story because with sandboxed play services things do work better and have more compatibility.
If not, I'll just have to flash it back to stock is all.
Thanks for the input, really appreciate it!