The problem is that the combo "closeup prescale" isn't supported. It reverts to "closeups postscale" but without throwing any error. You can do "all prescale" if you want.
Yes, that works. But what if I don't
want fixed-shape thumbnails, as well?
The reason for the 2:nd problem is because jAlbum applies the filters in a pipeline for performance and assumes closeups to be larger than thumbnails (so they are processed first). This could be made more clever I agree.
I was thinking that when we start getting into the larger folder thumbnails, this problem could rear its ugly head, especially when coupled with HiDPI. With ordinary thumbnails, it comes up only
very rarely, unless you're dealing with a user like
mrag, who has long had a preference for humongous thumbnails generated from undersized originals.