Yup. I gave up on trying to get Google wallet / Android pay to work on my lineage device. I got it working sometimes but it broke after update and just wasn't reliable enough to keep trying when paying for stuff. I'm not really sure whom they're protecting with this stuff -- the credit card processing companies, maybe?
How do you know it's carrier RCS? To the best of my knowledge they are only gatekeeping access to Google Messages private network, not carrier RCS? (Considering the very little number of carrier RCS that's not very relevant though)