Our plotter guy says 0.5mm is the safe minimum.

Little squares for free" is the problem, they're useless for seeing how a fabric moves. You need a sample big enough to fold and see the weight. I've had good luck asking fabric stores to cut me a fat quarter as a sample, costs a few bucks but shows the drape.

Grandmas always have the best hacks. Might have to try that knot trick myself.

Oh man, you are so right about that. I learned on the old wooden boards back in the day and it just forces you to pay attention to your feet. Everything plastic now is so forgiving, you can get away with being sloppy. It really does build a stronger base.

Yeah, that exact thing got me once on a cylinder base nut. The manual is right, you really do need to take up the slack in the mechanism first.