First, congrats to the team on releasing version 3.5! I immediately bought the upgrade. Lots of great improvements!
I was happy to see that MusicXML import/export got some attention. I haven’t played with it much yet, but several things I noticed immediately:
I exported to MusicXML a score that had a tempo marking at the start of the first measure. I opened it with MuseScore and saw two copies of the tempo marking appearing. This is a big improvement over the temp not showing at all, but it seemed like a bug. If needed I’ll send a score to reproduce the issue.
Fermatas still don’t get exported to MusicXML.
In the same file as above I had a “tr” trill mark over a note; the trill still wasn’t exported. I don’t think 3.5 adds ornament support yet, but I’m really hoping that could be added in soon. Would go nicely with the new figured bass support, speaking of which…
Figured bass doesn’t get exported to MusicXML.
All of these observations are based on me opening the exported MusicXML with the latest version of MuseScore; I didn’t look at the XML itself.