I also have State Farm on both sled and trailer but have Farmer's on my cars--that way my auto insurance should not be affected by a snowmobile wreck
Unfortunately, that doesn't work that way anymore. Insurance companies use a comprehensive claim system that shows them that a claim of any kind has been made. It won't happen as quick, your way, but it will eventually happen.
I've had this situation happen, rider paid for the obvious parts out of pocket, then when we saw that it was more serious than we thought, I claimed it on insurance. holy crap was I a noob... what we claimed that sled for is something I call regular wear now