It won’t be one laying worker... probably heaps, but by giving them good open brood (as you are) you’ll eventually shut them down. However, if you’ve that many got good resources in other hives you might be better off just making up a nuc and replacing the dying colony (of course you would need a queen).took some honey frames off my hives on wed.
my hive that was going great and i had not looked at since Dec was queenless.
there was some drone lava but no obvious sign of eggs.
i put a frame of eggs in that hive.
today i saw no sign of them making a queen cell and upon closer inspection around the frame of drone brood i saw some eggs laid on the cell wall.
i suspect a laying worker. i removed that frame of drone brood and put it in a nuc box away from the hive.
i am hoping the laying worker was on the frame.
i added another frame of eggs.
in a few days i shall check again and keep removing the frame with eggs if they are still happening.