Apple (if they were willing to expose a more wild side) should make an "M1 Pro Max Unlocked" board (or something like that) and just sell it as a bare, microATX board. It could cost exactly the same as the Mac mini for all I care, but if PC builders could use it in crazy cases and with liquid (or even liquid nitrogen) cooling, that would be so cool.
It would not surprise me to see some future Mac pro use the M1 in a desktop form with exotic high wattage but near silent cooling (liquid, air or otherwise). These chips are fantastic for video and media work and really need to get put into more workstation-like form factors.