It gives some discomfort if You want to change thumbs size, because whole database is rewritten.
My proposal is thumbnails views list with standalone options for each of them (e.g. thumbnails database file name). It could make work easier if soeme cm_xxx command would be attached to switching between this list entries.
P.S. 1. roentgen proposed on #TCMD Ctrl + mouse wheel functionality, but I think that could give problems with database files.
P.S. 2. Maybe it is the next step for my dream-like filemanager
