Operators who run tournaments, do you tweak the settings before the event?

I just went out today to practice on some of the tables for an upcoming tournament, and I was glad I did because I picked up some quirks that felt a little different from what I was used to. I got to thinking that it would be pretty unfair if they had just made some repairs to prep for the event and I happened to get there to practice right after (or especially if they made the changes right after my one chance to practice...)

I'm real new to maintenance/operation so I don't really know how much routine upkeep could affect gameplay, but either way it seems like it could be more fair to randomize some of those parameters -- playfield angle, flipper strength, kickouts -- so it doesn't advantage someone who's familiar with playing at that location. Does it make sense to do something like that? Is it common in competitive pinball?