I use focus for my follow, and I've been looking for a way to have the iwin button not based on focus.

I could modify the hex to be an iwin button - it would be 5 macros on 4 characters so not ideal....
So macro 1 would use arena1 on all shamans, macro 2 would use arena 2 on all shamans.....
I suppose I could use modifiers to reduce the number of macros.

I may have to just rebuild my whole setup - but thanks for posting this, really useful to know.