Really I suspect that's the only hard part. If we had accurate 3d models of the structure (well 4d, 3d models over time) it would probably be reasonably easy to estimate how much strain it can take, and how much strain there is... Maybe not predict-to-the-second levels of detail but at least to predict that a quake we see is likely to be a precursor to a much larger one or is likely that peak.

But getting that data seems... practically impossible at our current tech level.