Ive been wondering how to do the same thing without having over overwrite the default gallery in the templates dir. The fix suggested will work however it means we need to keep patching with future updates. Alex can put in the proposed fix in because this would break existing installations since gallery-extend and gallery-compact does not exist.
Alex, what are you thoughts on this? Any chance you can come up with a fix for this in the future releases? One possible solution to this could be something like this
[album id=x template=blah gallerytemplate=blah]
This would not break anything while providing the desired functionality