Off Topic - Spruce Goose

We have all seen the film of the Spruce Goose lifting off the water for a
few seconds only to be retired to its hangar never to fly again but I
wonder, what would its performance have been? Did Hughes determine in that
brief hop that the aircraft was no good or did ecconomic concerns ground it?

There are all kinds of aircraft performance analysis programs available now.
Has anyone ever plugged in the Goose specifications and determined how it
would fly?