thanks for asking.

Your observation is correct. This is a limitation of Apple's 
AppleIRController.kext, which is very inconsistent in the posting of 
button events for the remote:

- it emulates hold states for all buttons - except "+" and "-" 
- it sends release events for most buttons, but not for all. This 
includes "Play (Held)" and "Menu (Held)", so that the actual, total 
length of a button press can't be determined for those and repeat 
events can't be emulated.

It's nothing I can fix, except maybe write a replacement for 
AppleIRController.kext (shouldn't be too hard). The problem with that 
is that its installation would require to remove that part of the 
Operating System - at least from memory, which also requires root 
rights - and many (all?) other applications' Apple Remote support 
might break. I did not write anything in that direction for that reason.

Best regards, 
Felix