I have a Scarlet with both an Aluminum Canon mount and the Ti PL mount.
I've noticed that there is quite a bit of flex in the AL mount when focusing on more substantial manual lenses. In my case it's a set of modified Contax Zeiss, however I would assume its the same with current Zeiss, older Leica's etc. For tight shots, the flex is enough to cause movement in the beginning of the focus, even when moving the focus ring by hand.
My question is how much stiffer and more substantial is the Ti Mount? Anyone compared both. My Ti Pl is a beast, but a different beast all together given the size and scale of the mounts on the lenses themselves.