Okay, thanks for that
I recently purchased a new machine. My old mounting posts where at the 9th main (at the top, NSP) and in between 10 and 11 (mains, at the single-pass-grommet) at the bottom.
My new machine mounts just past the 11th main on both sides.
So now when I string bottom-up the racket really deforms a bit when I pull my last few crosses, which looks really worrying stringing at 32lbs, maybe this will ease my mind.
I have a stringprofi 69, loving the solid build and 1-knob-side supports. The position on the supports is actually not that different from yours (if I look at your arc7 video). Compared to yonex's (amazing) machine they're a bit "further out" towards the top and bottom.
The movement is small, but worriesome compared to the machine I'm coming from (my old machine had the quirk of producing a really fat and short frame when I finished all mains, only restoring to the original shape after the 6th cross. This new setup doesnt do that at all.)
However, I don't wish to derail this thread any further, I'll make some video's and start my own thread because maybe it's a discussion worth having