It's hard to spot those mistakes without an outside view.

Right, that makes sense.

To a degree, though I suspect that even in an uploaded mind it would be tricky to isolate and copy-out individual techniques...

True, but I wasn't thinking of using an uploaded mind to extract and study those ideas, but simply to plug the mind into your overall architecture and treat it like a black box that gives you the right answers, somehow. It's a poor solution, but it's better than nothing -- assuming that the Singularity is imminent and we're all about to be nano-recycled into quantum computronium, unless we manage to turn the AI into an FAI in the next 72 hours.