I have an ex factory CSBK
race bike that I've raced for the last 2 years, and yes it came with a clean title that is registered on my name. Don't be a smart ass now, I'd buy from Szoke a blank frame bike with a bill of sale any day. But if the frame has a VIN and Szoke/Kawi says it has no ownership, I'm walking away again. It's very simple, if there is a VIN on the frame, then there is an ownership, and it's registered under someone.
If your TZ250 has a blank frame, bill of sale is ok. Hypothetically, what if someone else's TZ250 got stolen many years ago, they see yours and think it's their old bike with a different paintjob now. You'll have some proving to do to the cops, you may have all the proof you need, but how much simpler would it be for a modern bike: "this is the VIN, here's the ownership," problem solved in under 1 minute.
If your SV was built from a Salvage, then it would have an "Irreparable" title frame than could be registered at the MTO, if someone had done the paperwork right from the start when it was built... And now, you wouldn't have to explain to potential buyers why it has no ownership and how you came into possession of it.
At the end of the day, anyone is free to do as they want. People can get away with all sort of crimes that have no consequences until they get caught. Why would I put myself at risk with the law over a
race bike that I'm BUYING with my money?!