IFMU, congrats on your homebuild. Not disagreeing with you, but your machine is based on a proven design, i assume. VS-300 had many technical difficulties to overcome, not all of which were foreseen. It underwent many major revisions, and suffered several crashes, as it was introducing new ground. I'll gain better insight in a couple of weeks.
Modern equivalent would be X2, which clearly is being taken at a sensible pace. Any future development of X2 capabilities would likewise take a similar effort - it is only prudent to plan accordingly.
Mart