Re: As per usual
"And since the purchase process is built around the fantasy of specs, it doesn't incorporate trials."
There was a time when bidding for a UK government project actually meant building the prototype system speculatively and passing trials with it. Only then did someone in the Civil Service/Government decide who was actually going to get some money to deliver the final system.
A canny supplier would try to make sure they were effectively "advising" the Government department on the writing of the bidding spec. Thus mandating their own system's unique features and capabilities.