I will be using a cropped clip all the time for many videos. Right now it seems I must eyeball centering it.
When I use the Left - Center - Right Horizontal fit, it does not affect my clip, so how does one center a cropped clip? It is treating the cropped image as much still including the cropped out area, implying I will never be able to center just the visible part.
Add your Size, Position & Rotate first and the Crop: Rectangle filter below it.
Adjust the size of the Crop filter and use a 2x2 Grid to make sure it is centered on the screen. The round handle in the center will snap to the intersection of the grid.
Then use the Size, Position & Rotate filter to move and resize (if needed) the clip inside the Crop filter, to the position you want.
If you feel you need to re-adjust the size of the crop, always make sure it is centered (using the Grid again).