Erase the flash work (system reset) before taking it to dealer. Just redo settings when you pick it up again.What’s the drill? I have never had a vehicle with a lifetime warranty, so this is new to me. After the warranty ends most people will do what ever they want to a vehicle, but while under warranty you need to be very careful. Most people need the manufacturer to continue to stand behind their product.
You’ll have more issues with suspension or emission mods anyway if you pick a dealer that wants to get picky.