Seems like I have a similar problem, is there really no way to completely restart Meat Circus? I've collected everything so far but I'm missing some figments in the Meat Circus.
As there is the "Victory Tour - Revisit all brains after completion" achievement I thought I can enjoy the game/finale and return to all brains after beating the game and collect all the missing stuff. Well, so far it worked fine and I revisited all brains and collected all missing figments, cobwebs, baggages until now, when only the last one, Meat Circus, was left. But everytime I enter the level it starts in one of the final boss fight rounds and I can't get back outside of the tent or restart from the beginning and there is no teleporter?
I already tried to run out of lives, but it restarts in the stage of the boss battle where I died. As my last savegame is quite old, is there really no way to collect the missing figments outside the tent after completion? =(