First, let me start by saying that version 3.1 is absolutely fantastic, what a massive step forward! I've been using MuseScore on and off but never for a large project (LilyPond guy here), but this version is really great and I am absolutely loving it. I really see myself using it for some larger projects! But I did find a couple of bugs and quirks which could be still improved in my opinion:
1) As discussed in https://musescore.org/en/node/278494, the only way apply articulations to multiple notes one must select these notes and then double-click on the articulations. This approach is fine, of course, though it might be a bit cryptic for new users to discover the double-click feature. What I find particularly anti-intuitive is that if you have a couple of notes selected and you click and drag the articulation to your selection, it will be applied only to the single note you above which you released it (or, if you released inside the selection but not above a notehead, no note gets an articulation). Why not apply articulations, lines, etc. to all notes in such case? If we make a selection and drag something to this selection, the intuitive behavior is that everything within the selection gets affected. There are some other parameters that have weird behaviors. For instance:
* select multiple notes and press 's' and a slur will cover all these notes. But select multiple notes and drag a slur from the lines palette and it applies to a single note and the one immediately after it.
* hairpins work a bit better though: dragging and releasing a hairpin above a note in a selection will extend it until the end of the bar. But using the shortcut '<' or '>' will add hairpins below the whole selection as expected.
* likewise, using articulations shortcuts with a selection (such as 'Shift+S) adds articulations to all notes.
My suggestion regarding this would be: first, apply the same behavior to drag and dropping as to the current keyboard shortcuts. Secondly, when a selection is made, drag and dropping anywhere inside the blue rectangle should apply the element to all notes instead of requiring a precise drop on a small notehead.
2) The Palettes pane is not in alphabetical order, which is good, but the order of the items in the list seem far from ideal. Why Brackets comes above much more important elements? Why are Dynamics in the bottom fourth of the list? Why are unimportant items such as breaths and pauses so high?
3) Hoovering above the lines category in the palettes pane gives a tooltip with the name of the objects. Cool, so the second and third items are called 'crescendo hairpin' and 'diminuendo hairpin'. But when I go to Edit > Preferences > Shortcuts and search for the keyword 'hairpin', I get no results. Those are called 'Add crescendo' and 'Add diminuendo'. Consistency between these would be great; in this case, 'Add crescendo hairpin' would be better.
4) From the manual, I understand that the only way to add dynamics is by click and dragging them from the palette on the left-hand side. The shortcut list does not give me any hits for 'dynamics or 'piano' or 'pp' or anything like that. Since dynamics can be edited as text, wouldn't it make sense to have a shortcut that would open a blank cursor below a selected note or below the first note within a selection of multiple notes? Perhaps the intended shortcut is 'Ctrl + E' for expression text, but the font in that shortcut does not match the dynamics font by default. Given that 'Ctrl + D' does not seem to be taken yet, why not use it to create a dynamic text with the correct font under the currently selected note/selection?
5) talking of dynamics, I understand that they can be edited just like regular text. This is great, except that the font parameters of what I type does not match the dynamics font. See:
6) It's really great that we get a miniature preview of the object we are dragging into a score as a cursor during the drag, but (at least in my computer and version 3.1) many of those seem to be broken. Below is what I see with a crescendo hairpin and with a 22a. Their top halves are cut. This happens to many other miniature cursors:
7) Perhaps it would be handy to have some vertical resistance when repositioning a dynamic or hairpin. I know that by holding Ctrl and dragging an already placed dynamic or hairpin I can move it only horizontally, but new users might not discover that so easily. A snappy (magnetic) approach could be good, so that consecutive dynamics stay within a line unless the drag is substantial in a vertical direction. They could also snap back in that position once one tries to move them closer to that position. This behavior can be toggleable, or one could use Ctrl to override it temporarily (i.e. disable the magnetic snapping).
These are just a couple of suggestions which are hopefully relevant and interesting to you all. Again, congratulations on this amazing piece of software.