Now, that said, the way you debug your submittal is to paste an entire page of error gibberish that looks like very low level database error output into an entry box they point you to. Sounds gross! Ewwwww! Well actually I've been debugging c++ templates since forever and hohum it doesn't bother me. However... every single time it decoded the problem and told me exactly what I needed to do. It has taken me 2-4 tries each year to get it debugged and then it sails right through. The final result I've fed into two different state forms and that has sailed right through too. All free, and not that much of my time.
Now if they can get the UI for normies painless, which I suspect is the main programming problem (I don't say that UI programming is trivial), this will take off like a rocket ship and the US can the join the coterie of civilized nations that do this for all their citizens.
I agree that it would be much nicer if they said "The amount of line 29 of Form ABCD does not appear at line 18 of Form WXYZ".
Even nicer if you never had to manually transfer amounts between forms.
I was thinking when I scanned the message was that I bet I could reverse engineer the problem from this back end generated text but why not do what the instructions say and just feed it into the parser box? And every time the next email message gave me exactly the thing I needed to do. It was cool, for a weird sort of nerd.
So no, I was casting shade where the process was right in the sunlight: I made the mistake, and the business logic caught it, and told me correctly every time what I needed to do to fix it. I liked the whole process a lot.