What kind of models do they use for reviewing the actual plans visually? A normal SOTA VLM like Gemini 2.5 Pro? Or do they stop short of that and just make sure that all the required documents are included in the submission?

I suppose for basic gotchas like clearance to a property border you could give a normal strong model the ability to zoom into an area of a plan image and look for something that says the distance measurement.

Or maybe they have trained a custom model that really understands plans in depth.