I have a note 4 too, I made some builds ages ago but very buggy....I just don't have the time/will/desire to try again...
I am noticing a lot of bugs in the AOSP builds on the 4. What ROM do you run on it now?
On Validus I have one very minor bug, that is also fairly specific. When adjusting media volume (game or movie) while in Do Not Disturb mode when you adjust the volume and the full shade comes down, when you hit the "Done" button it sends the shade only part way back up, pauses for a second and then fully retracts. Just a little odd, probably not really worth digging into but thought I would throw it out there.