Whoops! Sorry I missed your message.
I'm pretty sure that everything should be safe to continue as-is.
If you take a look, you'll see I've followed our established pattern of creating a new "local version" folder with the jars and settings and shifting some symlinks around.
I've experimented with Forge off and on locally for a while, and it seems to be pretty darn stable right now. Of course this all goes out the window for some time following an official Minecraft server update, but we can gladly switch back to the real deal by then.
Since we're not using anything that adds or changes blocks or items, maps should be totally fine and should be none the wiser about the change.