And how do you codify the threshold for what "very similar" configurations don't need to be tested and those that do?

That's what regulatory exemption procedures exist for, and it would be the logical next step if you had convincing hard data.

Every single regulatory process has them, so the fact that this very ranty article omits any mention of an attempt to use them is highly suspect.

I've worked with plenty of systems where for all sorts of reasons exemptions are granted for the express purpose of promoting innovation or recognizing a special circumstance.