Yah, I twiddled with the canvas size by manually tweaking VFOV, but that
isn't what I want. (It also gets untweaked by itself, or something.) I
should change my wording on this.
Right now we have the Autocrop tool, which crops out all image parts
that extend beyond an "inner" rectangular area. I'd like a similar tool
that crops out completely blank areas. So if a properly-aligned
component image happens to extend above or below other images, the
entirety of that image is included in the crop.
This would make fine cropping easier, since Hugin won't let us zoom in
when cropping. As it is on this image, I adjust the crop but can only
see the results by stitching it. This image takes approximately 8 hours
to stitch, so making fine adjustments is very slow.
I also wondered if reducing the blank areas of the canvas would speed up
stitching, but I don't really know how the canvas is related to the
panorama as a whole, anyway.
Maybe a Hugin Python script could do this?