Here goes my troubleshooting post, I'll try to give as much info as possible here to help those reading. I've done quite a bit of work already, and nothing seems to affect the issue.
-Oil change done 4k miles ago, oil level correct
-Spark plugs done 8k miles ago
-Valves have not been checked in quite a while, but I have my doubts that they are causing this issue. I may be wrong.
-Custom slip-on cat-back exhaust, with baffle
-Exhaust valve is still there and moving
-While the bike is on the rear stand, in gear, clutch out, the idle is around 2k RPM, with the wheel spinning
-At the above idle, the bike does not run smoothly (see video)
-When riding, there is little to no engine braking, most noticeable between 6k and 3k RPM
-When the RPMs fall, they fall fast, but there is noticeable hiccuping as they fall
-I'm pretty sure this is expected, but as the clutch lever is released, the idle raises to 2k RPM.
-Removed airbox, cleaned all sensors, cleaned air filter, reseated connections, reassembled.
-Removed and inspected AICV valve, looks perfectly clean, no gunk
-Removed PAIR system, blocked off with rubber caps and zip ties for now.
Here is the video of what's going on on the stand:
Thank you for your help, look forward to getting this fixed!