Figuring the setting on my rotary attachment

I have a c02 laser 150w. Ruida system. I process everything through lightburn. I have a roller rotary attachment.

My issue…my designs are compresses left to right. And I keep adjusting my steps per rotation numbers and wondered if that is the only thing i need to do.
The company gave me standard settings to start with. The steps per rotation:6500
Roller diameter:2.25

I have adjusted the SPR all the way to 10,000. It is widening slightly, but just wanted to double check with someone that I’m on the right track.

I figure that the measurement on my computer screen needs to be the same as what actually engraves on my glass. If someone could confirm I am doing the right thing and maybe throw some pointers in there I would greatly appreciate it!