In Den, if you have to do it twice in a row, just have 1 person exit the BC before the end to open the gate from behind. It takes like ~5 minutes to come back. Anyway, I dont think it's the best example you picked because it's probably the worst BC in game, unless you do Giddeus without warp >_>
In any case, a single 75 blm, rdm can solo all 4 lamp in ~15-20min and solo that BC. It's not that hard.
On promyvion (and every other CoP), they implemented a way to warp back before the BC after a while. Should have been done from the start, but it's not like they didnt fix it. Any party can get to top floor in 15-20min now (maybe 25 if they suck at dodging aggro)
Getting the coin back isn't hard or anything, but going to BC before wasnt really harder.
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