I think a good theory for me ATM is if it's a two post atty you can run a single center coil. I have confirmed what I thought and that single side slung
coils in 22mm (all I use) attys is just a weird feeling. One I can't quite place probably linked to balance - heating one side of the atty and applying air to both. I can't do single AFC. For me, the thump shines with a dual setup of lower resistance, straight wire whereas a stump shines with a single center setup of higher resistance and just the right twist of wire.
But 4 posts make duals so much easier IMO to mount.
They both have a place / use in my
vape life.