I've been in contact with one of the creators, HolyHeaven over the last few days and they seem to be fully on board with following our licensing requirements. They'll be introducing SCP-049 as a license-compatible DLC for their game instead of integrating it fully, to avoid having to release their entire game under the license, to my understanding. As far as I know, this is perfectly fine within the licensing requirements, and I'm unaware of any precedent that argues against it (after consulting with other members of our team).
I'll be waiting to see the final product/attribution page before I consider this closed, but overall, they seem receptive to our requirements.
They did ask if we would be willing to promote them/their game on our social media accounts, which I said would need to be run by Roget once they're finished, and that I can't make any promises on that front.