assuming that the proper government formatted forms are used
Doesn't currently exist. Who would design them? Who would pay for all existing data interchanges to be updated?
How long was your tax return last year? Mine was 35 pages once all the worksheets were added in, and that was a pretty simple return. Do you know how long a "standard" mortgage document would need to be to cover every possibility? The 30 pages Box mentioned is the simple ones. And they don't all have the same 30 pages.
leaving 5hrs and 30 minutes per day for backscanning
Backscanning of documents that predate the current system, and are frequently hand-written, not typed. Oh shit, all the historical paperwork would have to be entered by hand. And the stuff that's recorded electronically -- let's be wildly optimistic and say the last 30 years' worth -- still predate the standardized format, so every field has to be mapped, by hand.
Add enterprise OCR
So now you're not just trusting low-level bureaucrat to make a legal determination, you're trusting a computer program run by a bureaucrat.
a well designed document management system
Yes, because those are so easy to get right.
"It's easy, it's easy, it's easy. Lalalalala ... I can't hear you."
Not much of an argument there.