If someone doesn't want to be ignored, and they make their threads qualify under the TOS, but controversial enough, they're going to be quoted incessantly. The ignore feature only goes so far.
I think the issue becomes this: when a poster is essentially spamming up the L&G, the mods should step in. Open lav8 another thread, just for the PS. It's basic intellectual honesty: if you can't follow the rhythm of the L&G, then you should have the intellectual honesty of creating a separate discussion.
Don't ban: re-direct.