Ok this might be totally random but I think it might be possible to use the power of some GPUs to offload the heavy lifting. Imagine having a world with lots of stuff going on. It would be nice to have it offloaded to the GPU as the GPU can do calculations in parallel.
The problem with GPUs is that they use simd for parallelism, so the shader cores execute multiple threads in lockstep. This is only really fast if there are a huge number of threads that all do essentially the exact same thing, which is the case for shading pixels and doing machine learning stuff and lots of other things, but running minetest this way might be very difficult.
Most game engines are fastest when parallelized to a number of cpu threads, where branches in one thread won’t stall all the others
I just figured that some of the AI accelerators might be useful. I do hope that Minetest gets better multi core support. Most new devices have at least 4 cores at this point and the newer midrange chips have 12. (12th gen Intel)