Yes, this solves the stated issue about huge lookup tables.
> A planet size CPU that runs at .5 hz but can work on impossibly large numbers.
This doesn't make much sense to me, though.
If your goal is "any algorithm", you'll often have to go a lot slower than .5Hz. A hash-calculating circuit that's built out of a single mountain of silicon could have a critical path that's light-years long.
But if your goal is just "work on impossibly large numbers", but it's okay to take multiple ticks, then there's no reason to drag the frequency down that low. You can run a planet-scale CPU at 1GHz. CPUs have no need for signals to go all the way across inside a single tick.
Related to the fallacy of comparing what's slow in our world with what's computable in a simulation of it--there's no requirement for time to tick similarly.