Ok, I got your point but in the end, do you really want to play flooded maps with no sense? This first pictures show pretty nieces 3er steps combos ( one of my favors on pad ) and iin the second picture you are going to add some extra notes besides existing notes and over float the maps with jumps. I’m not sure how to pronounced it, but the fleer of the 4k game mode will fall. It is still a rhythm game and not a crashing your keyboard game ^^ And in the end, who cares about competition the 4 k mode and the 7 k mode? 4 k was originally made for pad users… and yeah I have been playing 4k for many years (also with pad (expert++), but I have been playing now osu!mania for a week and 7 / 8 k is a way more fun if you going to handle out how this works.
Edit: To say it clearly, I like your idea, but it is really hard to make good 4 k songs (and almost impossible for an algorithm) …and just putting some extra note won’t solve the problem ( well for me xD ). For a example http://www.youtube.com/watch?v=pu0iTSWnPdY this songs is pretty hard to play ( also for keyboard ), but this map isen’t flooded with notes ^^
Edit: To say it clearly, I like your idea, but it is really hard to make good 4 k songs (and almost impossible for an algorithm) …and just putting some extra note won’t solve the problem ( well for me xD ). For a example http://www.youtube.com/watch?v=pu0iTSWnPdY this songs is pretty hard to play ( also for keyboard ), but this map isen’t flooded with notes ^^