This deals with master/slave "transitions" - in this case a camera follows a path and then spots some other things to target..
First the "bad" case. Notice the abrupt camera motion. And why may you ask? Well it's that inactive>active>active>inactive thing.
We really need a far simple way to do this. If anyone is interested ... well I could explain.
But let's see the "good" case next
OK, this is the "good" case.
But it doesn't work as regard the 2nd target. MS thinks that an inactive thing is active (or visa versa) and chaos occurs:
And since you never know ... here's a 3dPDF with regard the camera motion near by the 2nd target
BTW: a weekend's challenge is included (kinematics) in the 2nd model: can you make these arms to push each other?