Facebook does not like alternative clients, but this workaround [1] worked for me. Signal is OK, and Telegram actually encourages writing alternative clients [2]. I'm happy to assist setting it up, come say hi on our MUC.

[1] https://slidge.readthedocs.io/en/latest/user/low_profile.htm...

[2] https://tdlib.github.io/td/

[3] xmpp:slidge@conference.nicoco.fr?join