main concern is that if someone (such as the user being discussed) had valid reasons for using another account to post something very sensitive then revealing this kind of information here could actually get them into trouble by revealing and associating that information with their main indentity

Dox-ing is essentially a form of witch hunting and in-fighting that is harmful to the community and system as a whole and I don't support it (thus I have now flagged this post in part to stop incentivizing such activities). That said, if you are in such a situation yourself, you would do well to better protect your privacy and not leave so many 'clues' around to be found.