I'm 173cm.

I just measured and highest setting is about 16cm from seat, which is on my lower back arch. Lowest will be at sacrum area.
The adjustable range is quite small compared to other chairs I've tested previously. 20cm is quite high.

if like tat probably u can try sihoo v1, i believe they both same lol.

What comfortability issues? I previously read that short ppl's problem is mostly knees can't bend over the edge of chair when sit in proper position (bum all the way in so back is properly supported)

Some chairs can adjust the seat depth to account for this. My Alterseat can, but the seat itself quite long. Even at 'shortest' setting my gf can't sit comfortably. She's 15x cm.
So unsure if you'd have the same comfortability issues.

Dont have bro, still thinking haha. But i saw 1 review saying sihoo v1 armrest is like no lock one? And will keep need to adjust.. this really bad i think.. if like tat better get alterseat..

yes this one is true. however the measurements will give you some sort of idea. Don't forget the chair you tried in showroom has been tried by plenty of people, the shapes and sizes may have been well worn and thus slightly softer and probably more comfortable. And also you will try to emulate as if you are sitting up right, and only get to try to test it for few minutes instead of sitting it for hours. So it's pretty difficult the gauge, but at least you will get some idea and the measurements will sorta help as well.