"A seed" is not a pollinated plant. I get the impression from the OP that the entire crop is seeded, in which case throwing the whole room into a veg cycle would have no effect whatsoever on either the quality or the yield of the pollinated plants, neither of which will be all that great regardless. Judging from what little is visible in the pics, assuming that seeds are forming in all those calyxes, I wouldn't waste any time finishing them. If there are some decent buds on there somewhere already, I wouldn't put everything on hold just to finish them on 12/12 because of grower lore if I could use the space left in the room to veg the next round in the meantime..