I'm not sure people can voluntarily self-modify in this way. Even if it's possible, I don't think most real people getting offended by real issues are primarily doing this.

Voluntary self-modification also requires a pre-existing desire to self-modify. I wouldn't take a pill that made me want to initiate suicide attacks on people who insulted the prophet Mohammed, because I don't really care if people insult the prophet Mohammed enough to want to die in a suicide attack defending him. The only point at which I would take such a pill is if I already cared enough about the honor of Mohammed that I was willing to die for him. Since people have risked their lives and earned lots of prison time protesting the Mohammed cartoons, even before they started any self-modification they must have had strong feelings about the issue.

If X doesn't offend you, why would self-modify to make X offend you to stop people from doing X, since X doesn't offend you? I think you might be thinking of attempts to create in-group cohesion and signal loyalty by uniting against a common "offensive" enemy, something that I agree is common. But these attempts cannot be phrased in the consequentialist manner I suggested earlier and still work - they depend on a "we are all good, the other guy is all evil" mentality.

Thus, someone who responded with a cost/benefit calculation to all respectful and reasonable demands to stop offending, but continued getting touchy about disrespectful blame-based demands to stop offending, would be pretty hard to game.

One difference between this post and the original essay I wrote which more people liked was that the original made it clearer that this was more advice for how people who were offended should communicate their displeasure, and less advice for whether people accused of offense should stop. Even if you don't like the latter part, I think the advice for the former might still be useful.