Turn off Chatty notifications for some (or all) Matrix rooms?

When using Matrix in Chatty (the regular SMS app on Librem 5), I get a notification of the same kind as for an SMS (sound+vibration) whenever someone posts a message in a Matrix room I have joined. For some rooms this means lots of notifications all the time.

I would like to use Matrix in Chatty but only get notifications for SMS and not for Matrix, or be able to toggle notifications on/off for each Matrix room individually, or get notifications only for one-to-one personal Matrix messages and not for larger rooms.

Is there some feature in Chatty for something like that, existing or planned?

Other ways to work around this problem?