So you mean if you put enough pressure on it it will move?
no, actually it's the other way around: the more weight the more stable the camera is. I don' think this will be a problem mostly. But it simply doesn't feel "right" that you have a $$$$ camera and a $$$$ tripod and a $$ camera plate but you still can lift and shake the camera.
Sometimes I work very fast when stitching and I think it
might be a problem that the actual camera body is not tight on the tripod.
I think the Max is actually designed for front rise/fall and lateral movements on the rear and while the stitching adapter of course works it's a kind of workaround if you compare it to a camera that provides 4-way shift on the rear.
Also did you actually find a problem with how the lens "moves" after you "lock" it?
are you refering to movements of the front standard when the stitching adapter is mounted or to the actual lens movements? As to the actual lens movements I think it's great. For my taste the gear is too fine... which also means it is too slow. I prefer the way the gear works for instance on the arTc, Rm3D or WRS... it's fast but at the same time fine enough for accurate adjustments.
On the Max, if you want to adjust a moderate movement, let's say 5mm or 7mm rise... you can first unlock the front standard for fast movements and then re-engage the gear by "locking" the clip to fine adjust. These are two steps, which is actually slow (for moderate movements! for large movements the "free" movements are of course very fast). Alternatively you can simply adjust the 5mm or 7mm rise by using only the geared movements. In this case the super fine thread of the gear makes things a bit slow. But I think this is just a matter of personal preference (certainly not a matter of precision) and I happen to prefer the Sinar/Arca/Cambo-way.