Rust Proofing for Canada

What do you think about Krown rust proofing and drilling access holes? I looked at my KL and could not find any high point (not drainage holes) on doors and rear hatch. The hood is the exception but the sound proofing panel must be detached.

IMO, drilling holes will break the paint surface and invite rust. Please don't tell me to consult with Krown because they will assure me it is fine, I would like to hear from those who has actual experiences.

This question/discussion based on my own experience with a Mazda MPV, the doors rusted from inside out. Once you spotted it, it was too late and I don't want it to repeat.

Many owners on this forum did not think additional rust proofing is necessary because Jeep has done that from the factory. It makes sense if you trade your car in every 3-5 years and your roads are not salted.