It lives!
Bit of a Hello World cut, I got it to calibrate, but it still needs dialing in i’m sure.
I also threw the brushless franken-router from Interesting find - brushless Franken-router setup in there, with ribbon cable extensions to relocate the board…because changing 3 major things at once never causes any issues 
This is 12mm ply, cut in 2 x 6.5mm passes (need to work out if I didn’t have it properly z-zerod as it’s not gone all the way through everywhere), at 800mm/s feed rate and 400mm/s plunge rate, using a 6.35mm (1/4") bit.
It was solid as a rock.
It probably is over-engineered and suffering for it slightly, the plunge rate might need tweaking (I was running it at quite a low speed and it bogged a bit in the plunge), but i’m pretty happy with that.
Now to try my luck with some full depth cutting…