I am currently working on an update, so I take another look at this, but meanwhile, here is a quick fix to avoid the root motion being re-applied:
Please open up AnimatorTrack_2017.cs file and change line #237 to be like this:
The change here, is actually var time = startTime - float.Epsilon.
This avoids the root motion from jumping around, but a better fix is required to the rest of the code to work more in harmony.
Let me know if that works for you.