I saw on ‘This Old House’ where they removed mold from an attic by blowing in chopped dry ice onto the mold. The mold dried up and disappeared.
I would think that projects with lots of delays would face this issue constantly. You can’t expect air spaces to just go into hibernation because other aspects of a job are stalled. Something also tells me the until permits are processed and approvals are issued that power cannot be turned on, etc. I’m surprised anything gets built anymore with so much regulatory interference.