While a range selection is active, many palette items have unexpected behaviour when double-clicked
When a range selection is active, and a palette item is double-clicked, many types of palette item do not behave as expected:
Text, repeat text, tempos and dynamics emit one item for every note or rest in the range selection. I would expect them to emit a single item for each part (or each stave?), at the beginning of the selected range.
It's possible to create a selection which invisibly includes the bar after the displayed selection rectangle. (I haven't been able to figure out a consistent way to reproduce this, but I encounter it fairly frequently.) This causes clefs and key signatures to encompass one more bar than expected.
One barline is emitted at the end of every bar in a selection. I would expect a single barline for each stave to be emitted at the end of the last bar in the selection (or at the beginning of the first bar, in the case of the "Start repeat" barline).
Codas and segnos emit a single item at the beginning of each bar in the selection. I would expect them to emit a single item at the beginning of the selection's first bar.
Incidentally, the "Add/Text" menu behaves in a way which is inconsistent with the palette. For example, I would expect the behaviour of the "Add/Text/Rehearsal Mark" menu item to be identical to the behaviour when double-clicking on the "Rehearsal mark" palette item. Instead, a modal error dialog is presented: "No note or rest selected: Please select a note or rest and retry."