Perhaps one could describe a perpetual motion machine as a time crystal on the macro scale? Can a time crystal do "work"?

A possible interpretation, like the heat distribution in space is about the same way its distributed in time; or a frog on a leaf, sitting there, not moving, same place in space and time. However the crystalline structure exist in time and space and the interpretation is bonkers! It's a crystal!

We can't see next before now; however, predictable.

I think sodium chloride is cubic and not hexagonal. Thanks.

It would be interesting to obtain a time crystal, without any external pumping energy source, but nevertheless out of equilibrium,in a quantum state with some zero point motion like superfluid currents closed on themself alternating spontaneously between two different states in time and space in an excited stable state?
zero point motion oscillations can appear in Josephson junctions or superfluids and could be used for time crystals ?

Perhaps one could describe a perpetual motion machine as a time crystal on the macro scale? Can a time crystal do "work"?

Not according to current understanding - it's just quantum analogy of the planet revolving the star: we can look at it for ever, but we shouldn't touch it in an attempt to drain some energy from it. The present implementation of time crystal is problematic after all: the quantum mechanics says, everything is in eternal motion, but this motion will be fully random (no "hidden" variables should be observable). The time crystals arise, if we constrain this motion in one or more dimensions - but it also requires to introduce some energy into system. If we force some ions to bounce inside the well cooled magnetic trap, then their motion will get less or more regular, but we need to exert additional energy for their cooling. So that in wider scope of experiment the existing time crystals aren't even perpetuum mobiles, not to say perpetuum mobiles doing usable work.

A time crystal in other words is a clock like an oscillating pendulum externally driven !!!