FWIW, i ran a k04 on my MKV GTI with stock mounts. Everything was fine until part out around 46k miles. K04 was on since 16k~.
It's a circumstance of your driving habits and throttle management. Even on a stage 1 or 2 tune, you can break certain components if you're doing launches at every red light. If your typical driving habits have the car at the track often, or doing some extreme spirited driving. Get the bolstered mounts, but you're definitely going to notice a the vibrations on stop/start and idle.