I’m not aware of any other calenderview for android that would solve your problem. But I think you can stick to material-calendarview.
As you already mentioned there is a pull request that promises to fix the issue you’re facing. This pull request however has not yet been merged into the main branch of the prolificinteractive/material-calendarview repository. That is, the changes are only available in the forked repository (anasanasanas/material-calendarview) until the pull request is merged.
The author of the fix for the RTL issue however provided a release of the material-calendarview containing his fix. You can try to use this in your app to get like early access to the fix. The downside is, that other fixes that have been integrated into the original material-calendarview repository in the meantime, are not available in the forked repository. You can of course fork the repository yourself and merge with upstream master, but given, that the fix is from April this year, I doubt that it is worth the effort as there won’t be that much important changes.
Additionally you should/could comment on the pull request and ask for integration. Probably someone simply forgot about it and will integrate in a timely fashion. The changes are not complex, have already been reviewed and the merge conflict is easy to solve. Thus I don’t see why this fix should not make it’s way into prolificinteractive/material-calendarview.
solved Is there any calendar view libs that support English as well as Hebrew(Arabic the same)