To clarify what I meant, it's not easy to do in the context of JSD because JSD is an existing program and we can't just hack random features into it without the source code. But we know the format for anims.j2a, so it would be possible to code a different program which, say, extracted some number of animations (and their accompanying information) from a(n already edited) .j2a file, saved them in a separate file, and then could later import them back again.