I tend to agree with Phil Bleazey that the banging on acceleration is from the Bevel Box nodding and hitting the chassis but it could be related to swing arm pivot bearings as well? I had this noise when I had the NVH mounting and some witness marks on the chassis to back this up but it went with the fitment of Phil's BB mount. Maybe the hybrid chassis BB mount isn't so secure as the Bleazey and still allows some BB nodding? It doesn't have the upper third stabilising mount as the Bleasey one does. The early and hybrid chassis type of mount has been known to bend and distort, Austin Smith had this problem on his M3W racer.
I have always done the swing arm bearings up tight enough to eliminate any play of the swing arm, when wiggling the axle fork end, then about an extra 1/4 to 1/2 turn preload. Not been a problem at that. If you load it more the swing arm tubes appear to deflect in, much more than I expected considering it is fairly chunky box section. I would be concerned about distorting the swing arm pivot points with the loading you describe. That said, if it works for you........
I like the new bearing bung and guide plate with the countersunk screws, another couple of critical mm adjustment available. Just a gnats .... clearance, similar to a "baw hair" only a smidge tighter 😁. Enjoy the non clunking and squeak free motoring.
