What is the best skim coating for polystyrene sheets?
If you attach (probably to the logs with long screws) metal lath



for the plaster to stick to, sure. If you only attach that to the foam, I kinda doubt it will stay, and without the lath I doubt the plaster will stay put long-term. Of course you could also just put drywall/plasterboard sheets up, again with screws long enough to hit wood (and adhesive, if you like.)