Ah, I see. We don't care at that level because we aren't trying to reproduce deterministic replicated simulations as the HFT industry often wants. SDRs have their own noise and the physical world is uncertain to where, as long as your algorithm isn't above, yeah say the 10^-5 to 10^-8 range in output, it's probably fine.

It's probably the determinism and reproducibility that's the key constraint in HFT settings. In other industries it's just generic textbook numerical analysis (analyze batched eps error), and then in engineering land it's "ehh good enough".