I've been waiting for CMYK support for years
Suggesting CMYK is holding something back is literally suggesting that the individual wants discrete control over the inks in the machine, without considering the colour of the inks, the paper colour, the saturation level of the paper, etc.
Clean plates for spot printing? Fine. CMYK painting? No.
Late binding has been the path forever, and is the only way forward. As a result, anyone suggesting they need CMYK has a debilitating grasp of how printing works.
> (color space? doesn't matter! Pick any CMYK!)
You realize that “color space pick any” has an implicit connection to the actual physical inks and what colours they print? Good.
As in it is a clear beacon that you don’t understand a shred of what you are replying to. I’m sure your professional(!) print runs that you have done have taught you that, though.