There are other posts about the very same condition, including my own but the experience I have does not sound as bad has your description.
I rode two different demo Roadsters before I purchased mine and both had the same vibration most pronounced at 2200rpm, and when I pull the clutch in just enough to take the free play out of the clutch the condition disappears.
My mate has a classic that was dismantled by Team Moto, the condition was a lot less when he got the bike back but it's back to the same as it ever was.
Mine is not bad enough that I can't live with it provided it does not get any worse, from the best I can find out the condition is just torsional vibration that is mot dentremential to the bike.
Be interesting to hear the results of your repairs.