A lot of it is going to be very, very situational. Some factions are going to have hard carries like Scyl, Arbiter, etc. that let you more or less just blast your way through the Crypt without that much effort, relatively speaking.
I don't think you need to get into the habit of moving your best gear around until you're able to finish off those 18-21 3*s for Crypts, though. But that is absolutely something you should do, especially putting your best regen/immortal on revivers and healers, for example.
I think until you're roundabouts where evilized is decribing (farming NM/UNM top chests, dungeon 20s, etc.) then we're not in the business of taking up super specific champs that will be in that FW only bucket, sometimes being usable in Doom Tower Secret Rooms.
What's your roster look like, out of curiosity?