midi patterns need a fill option

Hi instead of going into piano roll and copying then pasting to fill. We need an option to quickly fill up the same pattern to match the length of the longest part in the pattern. Sometimes midi files have longer or shorter lengths and the kick drum always has to be adjusted etc. If there was a way to set all instruments in a pattern to have a length of 2 or 4 bars every time that would be cool. This is used for making multi part patterns without going into song mode of course.