Using a TimeStretchCurve in an Animation Montage doesn't cause it to slow down or speed up when keys are added to the curve.
Link to API: [Link Removed]
This was reported and tested in 4.20.3 (CL-4369336). This was reproduced in 4.19.2 (CL-4033788) and Main 4.22 (CL-4435744)
Result: Nothing happens
Expected: The Montage speeds up or slows down as described in its API.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-64995 in the post.