Inconsistent working of different palette items

I recently got my knuckles rapped for describing the user interface in MuseScore as 'dreadful'. I was advised to make specific posts about specific issues. I have no desire to duplicate points that have already been made by others, but the number of posts on the site and the mass of results one now gets from even complex sets of search terms mean it is difficult not to say things that have been said before. With this caveat in mind...

Most, but not all palette items can be applied to a selected note or measure by double-clicking on the palette item. An improvement would be to have consistent behaviours throughout the palette.

Specifically...

Clefs can be applied with a double-click to a selected note or a selected bar: excellent. But time signatures can only be dragged to a bar: why?

Bar lines can be applied to a selected note or a selected bar, but in the latter case the bar line is applied to BOTH bar lines bounding the bar, which is usually incorrect. The effect of a double-click should be the same as that of dragging the chosen bar line to a bar.

Lines palette. Double-click on slur puts slurs between all pairs of selected notes: it should place a slur over the whole set of selected notes.

Double click on hairpins, 1st, 2nd time, 8va, Ped, tr etc. does not insert the item at a selected note or note group, yet dragging these items to the score clearly attaches them to a single note. A double-click effect would be welcome as a consistent facility for all palette items.

Repeats palette. For consistency, these items should be insertable with a double-click when a note or bar is selected: this doesn’t happen at present.