I did watch the video. I.ve seen it a month ago when I first installed mach 3, but did it again to see what I.ve missed.
I attributed the frame shake related to a gantry hard stop, with a sign that I.ve reached the speed limit on the machine, on the Y axis for example.
If it could accelerate and decelerates slower while running a g code, it could travel quite faster, but I don.t know if it.s possible. And honestly it.s not a requierment for me, as I.m not into large quantity production, but rather in custom or special products approach. For example, the first projects that I need are plexiglas stencils used to decorate some furniture with a traditional motif.

There is a guy called Roger Webb on youtube which does some decorative wood projects, and the cutting time for a 50 by 50 cm sculpture ranges between 2 to 4 hours in 2 cuts. I.m aiming for that, and I don.t think that is a high expectation but do correct me of I.m wrong.

I.ll test some speeds, but what am I looking for? How else can I know the max the machine can do?