Yeah, I would. I dont think you want to use chems all the way through flower.
Use up your last bug bomb, let it air out good, then get the ladybugs in there.
Put a few in there, maybe half at first, just in case the residual chems kill them, you dont want to have the whole box wasted. Thats the only thing I would be careful of make sure it gets aired out good.
But if you get some ladybugs in there they will go nuts on the mites, especially hungry ladybugs that have been in a box for a week.
And best of all, other then some dead ladybugs on the floor, they will have absolutely no other effects other than eating bugs.