On further investiagtion, this is a little more complicated:
-Sony HAS actually done the right thing by aborting its camera autoframing when it receives either a movement or visca preset recall command (in-camera preset)
-moving the camera manually in the vmix ptz tab does indeed cancel the autoframing, but requires ADDITIONAL presses of the directional buttons to move the camera. So the moveStart command is missed because it's like all it achieves is turning off the autoframing
-However, vmix preset recall won't even stop the autoframing.
-BUT, if autoframing is turned off the vmix preset recall works.

So I don't quite know what to make of this, but I guess it looks like:
-absolute/relative preset recalls by vmix don't stop the autoframing (likely sony issue)
-The ptz manual movements stop the autoframing but don't persist to actually move the robot.
So even if they change their firmware to have the absolute/relative commands abort the autoframing, the command might not be registered because all it's achieved is disabling the autoframing. This is of course speculative.

So it sounds like something that might unfortunately need to be addressed by both parties for these camera to be interoperable with vmix.