Unfortunately VW would use the tune as means of denying warranty for things unrelated to the tune, like the timing chain, for instance. My experience with VW dealers has led me to believe they're a bunch of crooks. If I'm capable of outsmarting them I'll do it.
I get that but this isn’t a mid 90’s Honda where you can easily swap computers. I worked at a dealer as a back counter parts supervisor. There needs to be a specific reason where a dealer will delve that far into an issue.