Ah that explains a lot of the strange things I noticed, I guess the player in some screens is actually sensitive to the release codes and since I wasn't hijacking those...
It is probably wise to add release for all other buttons as well. And looking at the hijack source yup, hijack expects to see number of buttons + 1 as the first entry (maybe because 0 means no buttons and 1 indicates all buttons?)

empeg_ui.c/h should probably be distributed along with vfdlib. Kirkis, interested in adopting them?