Similar companies are the credit reference agencies - Equifax, Experian, TransUnion.
Every time you request your data from credit reference agencies, the request is logged. My log has many such entries, due to repeated checking I did while trying to get corrections sorted, and due to the third party companies I used to help with this.
So I'd expect the same to be true for the customer rating agencies.
In the case of credit agencies, they say that information ("soft" enquiries) is not used to assess credit risk - and that it's either not made available to companies that process applications, or must not be used by those companies in the assessmment.
To be honest, seeing the kinds of errors I've seen, as well as seeing the inner workings when it is being corrected, some of it shows very shoddy, and in some cases seriously unethical processes (that the companies know about).
So I simply don't believe that companies are diligent about following the "must not be used" rule for data they "may" receive and are supposed to ignore. To convince me, it would require a level of auditing, or quality of audit, that companies plainly are not getting.
And these are companies I still do business with because they are good enough. Goodness knows what to think of companies I wouldn't do business with, if I knew about them and had any choice in the matter.
The only company to request proof thus far in the process is Zeta Global which presents a secure portal to upload your ID. However, to be honest, I'm not that concerned about emailing my ID if necessary.
"In order to process your rights request, Sift’s Privacy Team needs to collect the below information about you. We are unable to process your request without complete submission of this form and a copy of your valid government ID for verification purposes."
They havent provided me the Google form for Sift. I'll still submit it to them though. I've once been a Coinbase customer so they likely have it already.