Wow, cracking videos. I've wanted to see this done for some years. I had asked an expert on here a few years back if they could put such videos on a DVD, now you tube is so prolific that's a bit like asking someone to record on vinyl.
So who is Moto Phoenix, the guy seems like the sort of guy I'd happily trust to do gearbox work? Top class.
I love the bit where he gets the reassembly sequence of one of the stack of gears a bit out of kilter but very quickly realises it and puts it right, seemingly without needing any written reference as its presumably all stored in his head. Apart from need to have a hydraulic press and shimming plate and depth micrometer ( all of which would probably only get used once

) I'd happily have a go at this but I'd have to obsessively photograph and label each step/part as I'd be worried about putting something back wrong way and only realising it after re installing the gearbox, swingarm etc.- that'd be my nightmare, happened once when I replaced output shaft on a Honda and upon starting it up realised I'd damaged a bearing

( still comforted by the fact that the shop I got to replace the bearing screwed up on a balancer shaft setting and bike vibed like a jackhammer until they stripped it down and sorted that- thereby proving that its not just chancers like me

that get it wrong)