I don’t think it does it anymore. This was a while ago, like maybe 2 years ago. I used to just delete all the extra divisions and clone the match then pull the registration with “Import registration into a current match” box to avoid the issue. This is not a problem I currently have.
So what this other club (not mine) did was use the USPSA template with custom divisions. Back then, the app would add them as new divisions in addition to the standard USPSA divisions when you pulled the registration.
When a shooter walked in the day of the match and registered for the match in person, they would just add them straight to the score pad. When you add a new shooter, the default division is whatever is at the top of the division list. In most cases, Open. The default Power Factor is Major. They would add the new guy to the score pad, change the division, but forget to change the power factor. Everyone else signed up on the Practiscore website where the registration forced you to only choose Minor because there was no Major option to select. This is how walk-ons could end up being scored Major in this Minor only match.
The app definitely forces Minor if you select a minor only division, but if someone selected Major when registering on the website, it carries over. Once you visit the Edit Shooter screen, the validation kicks in and it fixes itself, but I’ve definitely had to fix a few PCC and Carry Optics guys set as Major. It would be nice if validation could be added to the website’s registration to disallow Production, Carry Optics, and PCC to select Major.
My experiences are purely from the Android perspective. If things are different on the i/OS, I don’t know. I do keep an iPad around for those times where I run into an Android bug that doesn’t exist on i/OS so I can work around it, but I don’t use it otherwise as this situation has become increasingly rare.