So let me just start with the statement that I think this is a terrific idea, especially for those like us here who typically have a variety of devices and also tend to push the envelope in using them.
Unfortunately, the reality is that NONE of the various cables we’ve purchased come anywhere even close to being even generally accurate.
To be fair, accurately measuring power draw on the USB bus can get quite complex due to various levels of standards, compounded by the fact that unfortunately the large majority of devices, even from the biggest OEMs, don’1 100% implement the various USB standard protocols and specs. (and thus why we have to “certify” devices).
Unfortunately, I’ve already seen in some other boards, though not here thankfully, people using these cables and drawing conclusions about varying devices, that really just aren’t based in actual fact.
Not to mention, that out of the 11 cables we’ve tried so far, only one was a fully compliant USBC 3.2 cable from a data spec perspective BUT that one sadly, is one of the worst as far as measuring power draw correctly (errors of greater than 140% in both + and - )
My new toy is a USB-C cable with a built-in power meter - The Verge