I represent a research group at the Computer Science and Artificial Intelligence Laboratory at MIT. For the past year, we've been doing a lot of work with local copies Wikidata and have experienced our own share of frustrations with Blazegraph. We are currently looking for alternatives as well. We'd love to hear about the directions being taken here, give our own input as to what capabilities we would hope to find in an alternative, and, perhaps, volunteer our services to help with the development/transition. Our work is a little niche so our recommendations may not be representative of the general need and our group is manned mostly by undergraduate researchers but we'd love to help if we can.