unpopular
Been spending a lot of time on here!
I mean, even if you could use spot meter, it wouldn't be good enough. If this type of metering does exist, you could ETTR as much as possible to get the least noise without blowing out the highlight and will also be a good starting point for people shooting ISOless.
I am not sure what "shooting isoless" means, but I agree with Josh. What you're talking about is pretty basic zone system stuff that has been around for the last 75 years.