3.0 Auto placement
There are some issues with auto placement that I think really should be addressed. Some are no doubt already being addressed in the issue tracker while others are not. I'm starting this topic in hopes of having a discussion on some of the issues.
The first problem I've seen is that auto placement often ignores the fact that there is a staff above it and puts items from one staff right on top of items from the other. MuseScore should either, adjust the distance between staves to make room, since this is what a human might do or move the text items so they don't cover items from the other staff if possible.
Once an item is moved and it's auto placement is turned off, it is totally ignored by the auto placement of other items. This should be considered an override and given the highest priority and the items auto placed around it.
Invisible items ARE considered for auto placement and should be ignored as though they are not there (I remember specifically seeing a bug report related to this and may have been fixed since I downloaded a nightly a few days ago)
Parts look terrible. I have a score with several Tempo Changes in a row that would overlap in 2.x and the tempo changes are arranged in a stair step pattern with the last one at the top of the ladder. The staves are far enough apart you could put a staff for each tempo change between them. In the near future I will look into more details and get more specific about this and other parts problems.