I don't do anything to my machines I wouldn't do to anybody else's machines. However, I've seen some shit done to mine that I would probably never do...but - I don't really care.
These things were out in the wild for 20 years in most cases before I got them. No telling what abuses they suffered, and they turned out just fine. Most pinball people are twits when it comes to babying these games, in my opinion anyway.......