Good Improvement

I've taken 1" off each tip of the MkI prod and made a new string, I can feel some increase in draw weight, but I'm not keen to try and fiddle about weighing it on the tiller.
It is certainly faster:-
212 fps using the 230 grain 14.5" bolt  (100gn point).
244fps using the lighter 156 grain bow pistol bolt which is only 12" long with a 50gn point (NFAS rules state 14" minimum).

It would be nice to get upto 250 fps, I don't expect to reach the maximum allowed 300fps
I'm pleased with the 244 for now but will experiment further.
Hoping to try it out on some 3Ds at the weekend, I have some 70gn field points, so I'll make up some 14" bolts with those and some low profile fletchings that should arrive today. Got to make a trigger guard too so that it is NFAS compliant. (Update:- done it!)

It will be interesting to see how far I can push the boo/Yew, I may take a tad more off the mkII or try heat treating the belly.
The bow is still comfortable to cock simply putting the butt against my belly and heaving, no need for a stirrup, which I've often thought a recipe for a pulled back. I think the optimum would be a stirrup of a suitable length so you can use your legs rather than bending your back. Too easy to twinge your back.
It's still slightly nerve wracking have such a highly stressed bow up at face level, but I think the failure mode would be relatively a benign collapse or de-lamination rather than the explosion you get with self Yew.