And it would be trivial to keep any "clean" account(s) they have on a separate IP,
Trivial, perhaps... but over time it's easy to slip and use an IP that's more traceable to you, which is why I said to publish all of the IP's that handle has posted from.
I can see some appeal to that, but surely any sane leaker will post using a restaurant's free wifi or similar - meaning their doxing gets associated with any other innocent user who happens to have posted updates from that restaurant, with no apparent link to their own isolated accounts?
Personally, I'd probably use the free wifi at the railway station on my daily commute - indeed, I do use it most days, for innocent purposes - or if I wanted to do something that might be traced, ride an hour or so on one of the lines and use another station on the network, using a randomised MAC address on a laptop. Anyone who was identified as associated with me then is completely uninvolved. Yes, maybe you'd catch a few low-level trolls, but you'd be falsely smearing a whole lot of innocent third parties - making the identification worthless anyway.