regarding KMBox - I've got both versions recently, B and Net.
KMBox Net is a hot steaming garbage and I would highly recommend to avoid it for now - I've got multiple issues during installation and, the main problem, on the most recent firmware, it duplicates and skips some keypresses even without simulated inputs. So it is basically un-usable at this stage.
KMBox B is totally different experience though - 0 issues as of now, I'll test it for a few weeks and will integrate support into the program if all will go well