Hybrid and alternate Inform 7

I was reading Appendix A, which I found on the Inform web site and this immediately intrigues:

“Quite interesting hybrid Informs could be built by making different decisions. Still, our design is not entirely free, since it interacts with the I6 template layer (the I7 equivalent of the old I6 library): a really radical alternate Inform would need a different template layer, too.”

I can’t tell for sure but this sounds like an interesting area for exploration! The document mentions that these initial forays (Appendix A anyway) was in 2008. We’re approximately nine years later now and so the obvious question is obvious: has there been much experimentation in this regard in terms of “hybrid Informs” or even an “really radical alternate Inform”?

If nothing else, it would be interesting to hear ideas around what these hybrids or alternates might look like.