Really all we'll need is the file that is getting changed, not the entire package...
Since the images are separate, this should be something that can be arranged for those of us that don't mind 'patching'.
Also, our resident package compressor has indicated that the DL size for this can be reduced below a gig, without reducing image dimensions or visibly affecting image quality. Dunno if he forwarded that to Boomatica, but that's definitely something that I'd be interested in in the future.
That and doing 'patches' where we only download the new and changed files, not the entire package each time.