The problem is MY city enforces the 2005 code, which doesn't clearly define what to do on existing circuits.
MY city does not define it in an ordinance.
I have many MWBC's in my home. I will talk to my inspector before I spend a ton of money on afci's.
This is for my home, I did the work myself, which I have not done in many years. I'm a commercial contractor.
I wanted some opinions from some "pros".
I got a few helpful replies, and a few smart ass replies.
Anyone need any good commercial help, post it.
I'll return the favor.
The only smartass remark in this thread are the two you posted