And we can't use mouse scroll up/down. I think it's possible by editing the template, just look the original 4.3 template and revert the changes that affects this menu.
We got a lot for free using the YUI libraries, but yes, the create-menu has it's limitations on large menus. I was hoping to see improvements appearing at YUI. In the mean time, here's a couple of workarounds that might not be perfect, but still worth trying:
Good idea, I'll go suggest that as an enhancement. Ideally it would be a user preference to choose one or the other, because I DO like it for the regular users if they have a limited number of classes available to them.
I don't have a good handle on how many classes a "normal" user would have; I've mainly just been developing and haven't had a chance to check out the user experience. I know I see around 200, though, and that's certainly too many for this style.