Aww. That sucks. Would be an interesting option to add to the game. In my eyes(I am a programmer, albeit not pro, nor amazing) it doesn't seam to hard to implement. In the .InI you would add 1 option.
Multiple Hitcircle: with a 0,1 value indicating yes or no.
and In the game, it would cycle from one to the next on each new combo, in order, and repeat(independant on combo colour, though easy to match up if work on). If I had the OSU! source code and knew what language it was in, I might just work on a prototype for the devs to work off of. But thats really asking alot.
I personally don't really see the need for a different skin on each difficulty(unless the skin is to try and make it harder, btu again I don't see much point). I'm more looking to add a little more depth to my map. I'm mapping a Black Rock Shooter song, and would, well was hoping to use the 5 icons, but I guess I'll have to pick one out.