If It were me I’d get it done privately whether it is someone on here, someone on a forum etc and be done with it and move on to many years of happy motoring
You’ve tried official channels and this it’s like the houses of Parliament, 10 different people get involved which result in 10 different outcomes
If you decide to get the key coded and did this, no one is ever going to search for it whenever it goes in for a service, repair, Mot etc
It’s never going to flag up as it’s so irrelevant
I did the exact same to my previous car, and myself and lots of others have no doubt tweaked lots of different things on the cars using OBD11 etc
So I wouldn’t be scared to go down this route
I’d just say thanks for your help, do what you want and keep it to yourself
Don’t be scared of the big bad wolf
When life hands you melons...,
Make melonade!