It's quite hard to up the tune so you get 20% more power... unless you strap a turbo on the bike... so not really an issue.
I newer did a "muutoskatsastus" on any of my bikes no matter what I changed on em.
Cops don't really tend to care about the bike mods unless it is an insanely loud exhaust.
My RC8 didn't have any indicators front or rear and no mirrors either.
Got a few tickets for speeding but newer even a comment about "missing" parts
Maybe I was just lucky.
The thing about performance mods is that insurance companies love to dig for reasons not to pay if **** happens so that would be the only reason to get official paperwork and inspection on mods.
Back in 2005 I had a Ninja which was heavily modified and only thing I ever got trouble for was the straight through exhaust
I do admit it was loud beyond stupid.