Currently, within a measure, editing is note-oriented. One can replace a note with a different note. One can use “delete” to replace a note with a rest. Or one can change the duration of a note, which results in inserting rests and/or overwriting following notes.
Measure-oriented editing, on the other hand, would be a mode that works within the confines of a selected measure. One could delete an interior note, resulting in rests being added to the end of the measure, rather than in place of the deleted note. One could insert a note before or after a selected note, perhaps creating too many notes for the measure (if there were not enough rests at the end). What to do with the extra note(s) is open to discussion. (One option might be to increase the number of beats in the measure, perhaps showing the extra notes/rests as grayed out or colored red). With measure-editing, one could change the duration of selected notes or note sequences, which would adjust the measure as above (depending on whether the change increased or decreased the overall duration of the change).
Currently, one can simulate a measure-oriented delete by cutting everything to the right of the note to be deleted, and then pasting it over said note. There are times when using the existing cut and paste operations is quite sufficient. That technique only works for certain situations, however.
For discussion sake, let’s say that I am composing a piece of music, and I want to change a sequence of eighth notes to sixteenth notes. In the current version of MuseScore, I would end up with a sixteenth rest in between each note. If I chose to fix it using the cut and paste method, I would need to do that one note at a time. Another example might be that I need to change a sequence of eighth notes to triplets.
Currently, the easiest way to make those kinds of changes is to insert a new measure, compose that measure from scratch, and then delete the old measure (which works reasonably in a single-staff system).
It would speed and simplify composing, if a measure-editing mode could be included in a future version of MuseScore.
P.S., MuseScore is a serious, feature-rich, high-end product, exceedingly well implemented and supported. I cannot imagine why someone would purchase an expensive competing product. MuseScore is a labor of love. Thank you so much for your efforts.