This appears to be tied to the integer time conversion. Converting in MovieSceneToolHelpers::CopyKeyDataToMoveAxis does not account for frame rate when converting tangents. I tested multiplying the tangents by InFrameRate.AsDecimal() and the results appeared correct.
The curve in Matinee will not look like the one is Sequencer.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-79741 in the post.