correct me if i'm wrong, but the only problematic thing with this hack is that certain meta fields might not be applicable to a given form (like the case stuff you discussed here: https://github.com/dimagi/commcare-hq/pull/1972#discussion_r8008482), and so would never have data submitted to it. So if someone chose the field for their custom export, it'd result in a wasted column but otherwise still harmless.