My next is actually set to my keyboard right arrow and pause is set to spacebar.
Then you could change the two 'Send,' lines to: Send, {Right} and Send, {Space}
Perhaps you will need to do some experimenting with timing pauses between the performed actions. (sleep 1000 = 1 second)
And there also exist separate commands for pressing and releasing a key.
So in case things don't work well, you could also try something like:
; Press Ctrl+Shift+n to skip to next song and pause.
^+n::
Send, {Right down}
sleep 20
Send, {Right up}
sleep 20
Send, {Space down}
sleep 20
Send, {Space up}
return
If it proves too problematic to get an AHK script running let me know, I can easily create a compiled (self-contained exe) version of this script for you that you can activate by just clicking it.
But it might be worth the effort to work it out yourself, AHK can be very useful for many more situations and applications.
And of course there is always the chance your wish gets implemented anyway…
edit:
Using media-keys might work even better since it is a more universal solution, and it doesn't need to have the MusicBee panel selected (in focus) to work:
^+n::
Send, {Media_Next}
sleep 100
Send, {Media_Play_Pause}
return