Whether or not you tolerate using RCS is up to you. Not supporting it for the sake of having a worse default option on the off-chance you can use the to convince them to use a better option is not a good reason to not support RCS.

Either you will have people content with SMS, or you will have people content with RCS. Which is better is obvious.

I am not on the GrapheneOS team but the community does push better options such as Molly/Signal and RCS is usually only advised as a fallback messenger.