The only real benefit of adding a C++ modding API would be performance, and that is kinda moot with LuaJit.
I disagree. A C++ API could also open up the minetest core logic to be used by third party tools, which has immeasurable usefulness.
I've considered trying to use minetest logic to generate worlds in the
Opensim environment. The Opensimulator uses a distributed architecture that could more efficiently serve up minetest generated areas. I also believe that its graphics capabilites would elevate what minetest currently offers.
I've been salivating over this project merge since I first heard of the Rift, and dreaming of worlds that could be more efficiently created and shared amongst users. I have generated 'block' type environments in Opensim that look really interesting. If anyone is interested, I'll grab some screenshots for various comparisons.