I think you’re over exaggerating the effort needed for tagging resources. Between terraform/pulumi/cdk and the tag tool, it’s relatively easy to make sure everything is tagged. Doubly so if you have a finance department who’s literal job is to go through and do that (or ask you for help with it)
Clearly your gender field is a boolean. Which means it can be either true, false, null, or undefined. Except in javascript where for some reason it can sometimes be NaN, but only when you try to compare two people.