I had an Idea playing around with the MYM launcher and I had a thought. It would be awesome if you created a modpack in the launcher that contained all the mods for all the packs that you host. I'm not sure if there would be any compatibility issues, but the Idea is that with this modpack, you could say play attack of the B-team for a few hours, then go to the lobby and jump into your current Agrarian Skies play-through without closing Minecraft.
That's not possible because the modpacks are useing different versions of the modpacks and different item ID's. It would be also confuseing if you have galacticraft items in your NEI if you are on the normal agrarian skies.