I'm having problems with a tremolo sign (see snippet):
1) It's too short - surely there should be a minimum size for it and it should be shunted to the next line?
2) It's in rather an odd place vertically: surely it should be either between the notes if they're well-separated as here or below both of them?
3) In printed music, tremolo signs between notes (not when attached to stems) are usually slanted, which stops them getting mixed up with the staff lines.
I agree that there are probably tweaks for these, but I'd hope that the defaults wouldn't need tweaking.