gif is not lossy. Ok, maybe you can say it's lossy if you have more than 256 colours, but you say it as if there is quality loss like in the jpg format which is not true at all.
And about the GGale developers not being open to feature requests, I think it might have something to do with them not being the original developers. Several months ago the ownership changed hands to some asian guys, and looking at their change log, it seems like they might not be interested in adding on to it, instead simply finetuning the existing features.