Another minor issue:
When I type xmpp:mymuc@muc.myserver.example?join in Dino or Gajim, it creates a link and when I click on it, I enter the MUC.
However prose generates something like "xmpp:" + "mailto:mymuc@muc.myserver.example" + "?join", i.e. on click, my MUA opens.
From Debacle on #general: