I wouldn’t!
My understanding is that the porn (yes, and the breach of trust, I get it) was the problem. So just remove his ability to attach files and it can’t happen again. And if that won’t do, there’s mod preview. Can’t be more effort than having to ban several new aliases a week, can it? Hell, I’d be willing to fucking do it myself.
Look, I do respect the mods and understand their position on this but, as far as I can see, virtually none of us (I’m willing to be corrected if I’m wrong) would be annoyed/upset by his return.
Sometimes you’ve just got to look at what’s been allowed to stay to wonder why it’s worth going to all this effort to keep one mostly entertaining mischief-maker out.