Sorry, can't test at the moment. Has this been addressed as well?
(Link to an old screenshot of overlapping notes on different channels. Same item, copied.)
Also, paste after smart copy (M.E. only) has been broken for me since 4.5. Easy to try. Make a 1 measure time selection. Put a short note toward the front/middle. CTRL SHIFT C. CTRL V. CTRL V. CTRL V. CTRL V.
Cursor lands at the end of the note. Remaining empty part of selection is ignored. Results in only a fraction of time selection being repeatedly pasted.