Cool!
I think all you've proven is that compression testers aren't a great absolute measurement for tuning and setup purposes, but I'm glad (some of) the laws of physics aren't being broken in your shop. I've also noticed that after a bunch of cranking engines will get moistened with fuel and oil and read higher compression.
If you have a tester that you use and can get repeatable measurements that kinda help you gauge relatively one setup to another, which it sounds like you're doing, that's probably good but saying stuff like '135 is better than 150' across the board doesn't work for everyone.