So after writing, I discovered they were asked about the problem with the Puma6 chipset and stated their job as they see it is mainly to test for standards compliance etc, and they purposely steer clear of performance in order to encourage competition and variety. Or some punt like that. (I'm probably mangling the message bit but that was the gist of it).
I guess there are such a huge number of devices and firmware releases it is an endless job to evaluate each for performance in depth (beyond top speed). Perhaps they are like cars before Ralph Nader. Unsafe at any speed? IoT devices would fall into that category for sure!