I wrote most of the below a couple (few?) weeks ago and never pressed send because I didn’t edit it and had concerns people wouldn’t receive it well. Hope you enjoy the unedited honesty (see: autism).
EDIT: Welp… I was right, it was not received well, or the automated filters caught it as spam so here’s the nuts and bolts only. Being on the spectrum is a recipe for getting banned and having posts blocked on forums until the mods realize you’re actually just an honest-to-a-socially-awkward-level nerd.
My incentives: The only message I am incented to sell is “you will benefit from personalized nutrition recommendations.” I have no supplement company affiliations and never will.
My very forum-public pre-app, pre-youtube, history online should reveal that my stances have remained unchanged and unswayed by profit motive. And will always stalwartly stand in favor of saving people money, even if it causes me literal bankruptcy, which it may.
Here’s an old post that spells out my mindset on a few related things. 
I share your skepticism deeply.
Regarding my experience with sweat tests: first, yes, my education certainly covered them, haha. Ironically, while I have never myself executed a sweat test nor actually seen one performed, I have held the technology/devices in my hands, studied the engineering and patents of the devices, understand how they are used, performed, analyzed, etc to the degree that I have been consulted by companies designing wearable sweat and biomarker measurement devices. I’ve read most of the scientific literature ever written on the topic.
Just for clarity so the above doesn’t sound like promotion: I don’t plan to ever make or sell or profit from such a device’s sales or usage and have no affiliation with any such company and never have.
My wife, an RD CSSD, has been party to hundreds of sweat tests in the field (maybe thousands) and specializes in endurance sports as a pro triathlete and pro MTB’er.
Hope that’s a helpful and very transparent light on some of my background!
Devil’s advocate tidbit:
(maybe would be better to add this bit to the Unpopular Cycling Opinions thread)
Some of the folks with the most published studies are absolutely some of the most biased folks I know. I’ll spare you the diatribe, but suffice it to say: publications mean utterly nothing in terms of intellect and lack of bias on a subject.
A much better ‘tell’ for lack of bias is the absence of specific narrow affiliations that benefit from certain narrow messages being peddled. I’m biting my tongue to avoid naming names of most biased researchers of all time in this area, but a few of the most prolific have gone on to shape what our industry thinks and does about fueling after deeply affiliating with certain products having certain formulations, if you know what I’m saying!
One researcher who I find to be the opposite of that, so far, is @timpodlogar. AFAIK, he resists becoming financially involved with any nutrition companies so that he can remain neutral for the people, and I would imagine he’s had many offers or would if he opened the door to it.
