nobody cares but i believe haechan and mark have very good muscle memory. it exists when you practice and clean a same damn choreo repeatedly, it naturally comes back to you after marking through the moves just once after not dancing it a long time

so ig it’s not surprising that they remember all their choreo for diff groups but like i said the blocking is the crazy part. haechan doesn’t only rmb his own positions, he rmbs where each member shld be at and he proved it through all the weekly idol random dance segments

in conclusion haechan is a god