Before doing the top end I'd drop a teaspoon of oil in the cylinder and see if it changes your compression. I had a similar issue with one smoking like yours and it would actually glow the exhaust header red after running for a few minutes. Come to find out the spark plug wire was corroded and was not firing all the time, dumping excess fuel into the exhaust, and the excess fuel was washing the oil from the cylinder wall, breaking the ring seal and burning oil. Something to definitely check before taking the head off. If that's not it, the fact that it looked to puff more smoke when you accelerate, I would lean towards rings and not valve seats. Good luck and great job with the videos!
Yea the had a aftermarket filter in it. I always use the oem filters. Also I use a little bit of grease around the filter were it slides onto air box to help it from sucking any dust at that connection. Biggest down fall to these early 800’s is dust and dirt.