I think it’s extremely annoying and tiresome to have to manually insert grey silent notes in order to properly arrange a melody or to have to manually insert a properly-sized silence after doing something as simple as shortening a existing note’s length.
“Silence notes” is a behavior that only makes sense in old-school “fixed” trackers, arrangers and such, but certainly not in a modern arranger/sequencer scheme, which is the one TheoryTab uses. It’s an extremely awkward way of doing things in that environment.
Why not just let us independently arrange, resize and position notes anywhere along the length of a tab, and just automatically fill any existing “gaps” with invisible grey silent notes of the same length of the gap?