There is no version “Between”, if you were on the 4.18 migration branch it wouldn’t compile for you at all.
I actually don’t think i’m going to change the tracking method in 4.18 after going over it yesterday, but adding the foot / snap turning to it should still be done.
Regardless the parenting works, you may be confusing the tracker no longer moving (staying at 0,0,0) with the parenting being broken? Just replace the old tracker with a motion controller or grip motion controller.