Maybe I’m very far off base here, but you have made a cnc machine, so the version not to be called V2 could include a few CNC’ed aluminum parts. Or at least make them optional. Much smaller parts with more rigidity. I’m also wondering about the use of belts if you want to cut steel with a 2.2kw spindle. GT2 belts stretch!! For the value conscious all thread could replace acme leadscrews, or even ballscrews. China sells acceptable ballscrews with antibacklash nuts, and anti backlash blocks have been made for allthread. These are just a few random thoughts on a version that eats steel. 4th axis should be next, too..