That’s what I do, and no Play services on my device. Then you just need this if you want to be able to click on the photo preview and see your recent shots without having Google Photos installed: https://apt.izzysoft.de/fdroid/index/apk/com.google.android.apps.photos

This is the closest I’ve been able to find - JMP which is used in Cheogram, a FOSS XMPP app, was working on it in May but I messaged them about it recently and there hasn’t been much development on it unfortunately. https://blog.jmp.chat/b/may-newsletter-2024

They allow you to have VOIP numbers and even a data only SIM with no KYC and pay in crypto if you want so it’s a pretty cool project overall. Maybe if more people message them about RCS it will become a higher priority.

Same issue on v20231128