Wife, mortgage, mouths to feed (ie destructive little monster cats lol).....ect, ect.......Tuned Stage 1 at 1000 miles, went Stage 2 at around 6000 miles, almost 8000 on the odometer right now..... blah....blah..... lol....I know you aren't concerned about actual tune failures. You are worried about that dick dealer that wants to weasel out of anything and everything.
Seriously, there's nothing anyone can really say to help you with this decision. This is just a gamble that must be taken or you stay stock. You can go talk to your dealer you use for service, ask them how they feel about and treat mods. Use specifics, like what if my water pump fails, what if my intake manifolds blows a flapper, ect. That will offer some piece of mind....... but then there's this. Your on a trip, far from home, issue arises and car is towed to closest dealer, not yours....... this dealer is a dick, now you have to fight.
There is no foolproof guarantee....... this is part of modding. No guts no glory.
I blew a CV boot at around 4 or 5k miles..... tuned and lowered. I prepared myself for a fight, doubted it would be an issue but always be ready. My wife flipped, stated redoing the budget to adjust for having to pay for it :laugh: but no issues, replaced under warranty with several apologies from the service writer for it happening and the delay in getting the boot. But I was ready for it.
If you aren't ready for the fight, if your not ok with the possibility, then you shouldn't do it.