Wait, so you're telling me that guy just straight up called you out like that on a real job? I've seen guys get sideways about getting critiqued on deck but it sounds like he actually gave a damn about you not smashing something. Honestly that pendulum thing is no joke, I watched a bag swing a 300 pound valve right into a pipe rack once, tore the whole setup down. Good on you for taking the feedback, a lot of guys would have just gotten defensive and kept doing it wrong.

Gotta disagree with you on this one. A marble test only catches big obvious slopes, not the subtle stuff that really matters. I've seen houses pass the marble test and still have mold growing behind shower walls or in the attic from bad ventilation. Modern moisture meters and thermal cameras catch problems way before a marble will even twitch. Plus, any halfway decent flipper knows to level the tile floor first, so the marble trick just gives you a false sense of security.

Heard a similar thing from an HVAC guy I know who's been doing this since the 80s. Said the seal swell comes from mineral oil over years, and synthetic can wash that out fast on old rubber. Worth checking your supplier's spec sheet next time you stock up.

Firmware actually fixed a problem that shouldn't have been firmware related?

Gotta disagree a little here lol. Replacing the whole shutter is a pretty big job and not always worth it unless you're doing it yourself. On older cameras like that, you might end up chasing other issues after the swap - like timing being slightly off or light seals crumbling. Sometimes it's cheaper and easier to just buy another used body in good shape.