After all this I'm probably going to end up carrying a tokarev. I would see the specialty rounds as something carried in a third extra magazine, my last ditch ammo, probabably kept in a different spot so it's not confused with the others. Normal SD rounds in the other magazines.
There really isn't a need to do that. The chances of you encountering an armored assailant are pretty slim. Even if you do, you can identify it early on and make adjustments in your response as needed.