Anyone an expert on crawlspaces?

[NYC_SKP]

1. I would talk to a local building supply house, and older person with experience.

I think your region and climate and details of construction might indicate different solutions than others might use.

Ordinarily, I think thick foil faced bats stapled in place would be fine.

The only installation I've ever seen done used chicken wire to keep the bats up, not a bad idea since gravity will, sooner or later, have your insulation hanging down in places.

Check with the locals, they'll know what to do. And try to get more than one opinion about it.