From @brathouz link above.. "One reason why space-time crystals are interesting is that their periodicity in time makes them natural clocks. So there should be

From @brathouz link above.. "One reason why space-time crystals are interesting is that their periodicity in time makes them natural clocks. So there should be plenty of people with more than a passing interesting in making one." So I took from that, yes, this could be an alternative to atomic clocks.