I love this idea, and so far it seems to be working very well... I see this way as not interupting r/p, especially if there is an intense r/p going on, this way, you can PM back greetings... As for not being able to get into r/p as quickly as you would like, I don't really see that as a problem.. In fact, this way, while you are greeting in PM, you can see what is going on in camp so you have a better idea of where you could be doing and what not... ~grins~
Also, this is easier to explain to the new slaves and thralls that are coming into camp, as we all know greetings are and have always been a top priority to those new incoming slaves and thralls..