My patch test fails are legendary.

Totally agree. That mix of old and new knowledge is what makes a real tech now. You're not just a parts changer, you're a problem solver.

My old service truck always has two spare fuel filters for the main engine. We were on a logging road in Oregon when the primary one clogged with junk from a bad fuel load. Swapped it in ten minutes and drove to the next town instead of waiting six hours for a tow. That fifty dollar part kept a forty thousand dollar truck moving. You just don't risk being stuck over something that cheap and easy to swap.

Foil is the problem, try butcher paper instead.

Wait, is the pen lag REALLY that bad? I used one at a friend's house and it just felt like a normal drawing tablet. Maybe some people are just super sensitive to that stuff.