From what I know the reason we have infinite vacuum energy is because according to Quantum Field Theory at every point in space we have something analogous to a harmonic oscillator but since the Zero Point Energy of the quantum harmonic oscillator is non-zero, vacuum energy becomes infinite to due infinite points in any finite region of space.
But if we quantized space shouldn't we get rid of this problem since there would finitely many points in a finite volume of space thus the vacuum energy would be very large in any finite volume of space but still finite because the sum of the points is finite.
Or would we still end up with infinite but countable points that are quantized. i.e would we still end up with a bijection but one that is now a bijection to the rationals instead of the reals from any finite volume in space.
Answer
Yes, the vacuum energy of a spacetime lattice with finite spacing and periodic boundary conditions within a box of finite size is finite. One would not call this "quantizing", though, rather discretizing because we are not carrying out any "quantization procedure" in the sense of going from a classical to a quantum system.
In this approach, the finite size of the box takes care of infrared divergences since the largest allowed wavelength is that of the total size of the box, and the finite lattice spacing takes care of the ultraviolet divergences since the shortest allowed wavelength is of the order of the lattice spacing.
In fact, this is actually underlying QFT in most approaches - the path integral is defined by a limiting procedure on such a lattice (and physicists typically don't care whether that limit actually exists).
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