Did your installer actually run the load calculation, or just promise you'd save money...

5,000th haircut and nobody clapped" sounds about right, my own milestone was burning toast AND the fire alarm both at once.

Man, that bushing thing gets everyone at least once. Same thing happened to me with a cheap kit, the sleeve spun free and chewed up half a sheet of birch. Six hours feels about right, especially when you keep blaming your own setup. I'd say check the locking screw before every single run now, not just when it feels wrong. Maybe it's just me but the cheap jigs always need way more babysitting than the pricey ones.