As far as I can see PlayCanvas releases are being checked by test tools on code level.
Since releases are mostly stable on code side, and sometimes we only experience unexpected views or displays scene, I have this idea where we test an example scene with a NodeJS application.
This NodeJS application will simply take screenshot of scenes for different cases and compare images with original one. If similarity is below %70, system simply warn Github users (contributors) about that.
Engine is very stable with it’s current state. So I believe we won’t see any changes the way how graphics work. This similarity check can prevent potential bugs with different cases quickly.