Hello! I had the same problem and oddly enough came up with the same solution, however I can’t seem to get a smooth camera motion from this because value at seems to ‘jump’ to a given keyframe of the camera. While the video is frame blended and flows smoothly, the tracking points jump every few frames depending on how much the original footage is stretched. Is there an alternative way to time remap a camera?
I’ve tried putting the camera by itself in a separate comp, time remapping the comp then linking the values of that camera to a different one, but I still cant seem to get time remapped values.