Thanks and no worries, in case anyone else comes across this, I ended up with:
Changed the springs: 2 * 0.6mm WD, 8mm OD, 300mm length springs cut down to approx. 250mm
RHD Hop Arm and adjuster set (highly recommended, it seems much better) for the APFG MCX
4UAD bucking
UNICORN - 6.03mm Ultimate Precision Inner Barrel Set For GBB (285 mm) - I had the 11.5 version.
A tiny wrap of Teflon tape around the bucking and the barrel out of habit, not sure if it makes a difference
I had to sand down the bottom of the nozzle (the stripper and the gas router) as magazines were too tight. (Might just be a bad batch of nozzles)
Thread lock the screw that holds the nozzle in place in the bolt
I also got the reinforced RHD barrel/handguard support, seems much better.
So far happy with it, not used it for a game day yet but test firing out to 35ms it was pretty good.
