Speakers and headphones as you know have big differences from each other.
agreed
With other classes of devices, impairments get very small to non-existent.
Now that statement takes a leap of faith, no, a chasm of faith. Other classes of devices mean EVERYTHING except speakers and headphones? Please explain and if you have some evidence of this please post a link, don’t worry if you don’t have any of the accepted evidence here ,I doubt you’ll get banned.
I simply don’t have the time or resources for this type of testing.
Agreed, you are "financially independent" right? Outsource it or don’t do the review. Basically it reads like you are simply guesstimating these results and presenting them as fact. If I tried presenting such a sloppy review on ASR you know what happens? It rhymes with "tan". :)