As numbers get closer to being fixed, I thought I'd have a check of compression ratio.
Doing calcs with recessed head and big PBT does get a bit fiddly, so to make it easier to picture (and reduce chances of me making a cock-up) I've taken deck reference point as being underside of squish band on head, and PBT (finished deck height) as squish (0.9mm). To check I was getting it right, I compared my results for 0.9mm Squish with BGM's; it's pretty close. I think my slight increase is either my method of measuring (I've done my best, but I haven't got lab kit; just basic stuff), the reduction in my head due to tidying up the detonation marks off the head squish band, or BGM's dome volume, which I just don't agree with. Anyway, the purpose of that first one was mainly to make sure I was using the right numbers, which I am pretty confident about.
Having established that, I did a new calc for the mods to raise the cylinder (and reduce head gasket) by 0.4mm, and cut the Exhaust port 1.6mm higher to get 125/181/28 (I note you say it may go higher; I'm just checking and keeping up to date with what we have now).
For 125/181/28 125/66, I'm getting CR=11.34:1 and CCR=7.03:1.
I'll just leave that there; the weekend forecast here is very good, and I have outdoor jobs to do on my scooter tomorrow, and hopefully time for a ride on Sunday, so, especially as I'm part-way through doing an engine build shopping list anyway, this job goes onto back-burner for a few days.
Here's images of method and working; should I clean the squish band more? I can take more out of the bowl to tweak the head volume if necessary:
As accurate as I can; 19.5cc
Checking against BGM Data
To latest tweaks for 125/181/28