I recently shot a project in 5k with a 4k extraction guide... so I have padding to do some fine tuning on camera moves. Luckily there isn't much to be done with traditional stabilization. Everything was very smooth and shot on sticks. But there are a couple of moves like tilts and pans that I'm trying to fine tune. Here's an example...
The shot starts out locked off and then tilts down to a second locked off position. Now what I would like to do is make the end of the camera move a little softer. So just slow down the last 20-25% of the camera move. And I need to do this without change the beginning and end frames.
I would first use Warp Stabilizer for smoothing the motion with relatively high settings and see how it looks even without any slowing down. Warp stabilizer may slow the apparent motion down enough so that it looks fine without actually having to slow down anything.
If it turns out you actually need to slow down the end of the footage while keeping the beginning and end frames the same, you need to speed up something else, and this means time remapping. I would find a point where there is the least amount of motion and speed that part up, then slow down the end. Or you could speed up the entire beginning part and see if it works better. This depends mostly on what is happening in the footage. For example, if there are people doing something, it may become very apparent the footage is sped up or slowed down. Use pixel motion for frame blending.