As someone with keen interest in physics (and a bit of training) I find speculation about "discrete space" disquieting. It's the level of abstraction where intuition about space breaks down, and you have to be very careful. Remember that coordinate systems are short-hand for measurement. It's one thing to admit fundamental limits on measurement resolution, and quite another to say that space itself is quantized! Mostly I get around this by not thinking about it; most of these theories are only testable in atrocious and unattainable conditions, doing things like performing delicate QED experiments at the edge of a black hole.

I don't think your "voxel" intuition can be right because it's a small jump from that to (re)introducing an absolute reference frame.

> how does one voxel communicate to the neighboring voxel what to update without passage through ‘stuff in between’ that doesn’t exist? Heh

That kind of reminds me of the 'aether' that was once hypothesized as a medium of transmission for light and radio waves [0].

Also, voxel's communicating sounds an awful lot like a higher-dimensioned cellular automata.

[0] - https://en.wikipedia.org/wiki/Aether_theories

Stephen Wolfram was right all along