Not really, I'm afraid. Maybe discuss some way to set up a critiquing circle for those as well and keep that separate from the challenges?

If you do decide to go ahead and you're sure you want a WP blog, I'd recommend looking at a comparison of self-hosted versus WP-hosted and see what features weigh heaviest for you since you're already paying for the website anyway.

I'm glad they're giving you something to consider. ^-^