Re: how much compression can these things take?
Lets not forget that these engines are cheap Chinese garbage; designed on the cheap, manufactured on the cheap and sold to a target market that are prepared to pay for unreliability that's built into a dirt cheap price tag.
The standard engine is built with only just enough reliability to get you to your destination and from that point it's only hope, luck and prayers that will get you home again.
Increasing the engine compression ratio will add a bit more stress and consternation making the decision to try for an arrival time 3 hours short of your ETA.
There are others in this forum which may be able to give an alternative view with regards to increasing engine compression and performance modification; some achieving moderate success.
My opinion: leave the engine completely standard to preserve what little reliabilty they have.
I need to add a disclaimer on my words: please don't place any weight on what is written, nor act on any opinion expressed by the author as i've been listed as giving downright lousy and uneducated advise that's not wanted or needed.