Here is my suggestion:
Add option to show tray tip before song change (current option we can show after song change)

Let me explain my problem, maybe you have a better idea:
I like to rate songs after hear, but only know that music is over when start next music.

Thank you for all your good work.

It can be done rather easily, though I'm not sure I want to add it to the already long list of options. Maybe as a tiny plugin ? Though it also add to the list of plugins.

Note, that if you just edit the rating of the previous song, there are other ways. You can right-click on the "previous" button to get the list of recent songs, and then right click on the one you want to get its context menu from where you can edit the rating.
You could also edit your layout to put the previous song somewhere like the Conz/"Conz Glimm (different controls)" layout

I know the thread is rather old, but:

I also like the idea to add an option for this!

Sometimes shuffle jumps to a song I don't want to hear, and with a traytip before the song change would give me time to skip the song...

About the concern of having another option in the long list: I think that's a feature of gmb having options for nearly everything!

Regards, staubi