Ok, last night I got a little carried away... I'm trying to be really really reeeeeally patient and not use too much BP, since my skin needs to completely readjust to it. Anyway, last night I put on perhaps a little more than I ought to have done, and this morning I have two areas of fairly irritated skin that resemble the rash I got when I was reacting to the BP the first time. They don't seem to be too terribly irritated, but they do itch and they feel a little numb, so I don't think I can write this off as normal BP irritation.
Interestingly, my chin wasn't the area that reacted (although I'm being especially careful to use as little as possible on my chin). It was the bridge of my nose between my eyebrows, and my right temple. It is also worth noting that last night was the first time I used the Acne.org moisturizer in conjunction with the BP; I was out of it so I was using an organic lotion (natural but possibly comedogenic) with jojoba oil and an olive/aloe/comfrey salve. Perhaps there is an ingredient in the moisturizer that combines with something in the BP to cause my reaction? Or maybe my skin just reacted more because I created conditions that were more similar to the original reaction.
I also used clindamycin yesterday morning, but only on my chin an under my nose; nowhere near the irritated patches that have since developed.
I'll leave the irritated areas alone for a few days and see how they heal; in the meantime I'll continue with BP in non-reacting problem areas and clindamycin on my lower face in the mornings. I'll keep using the Acne.org moisturizer for now as well.