"Frame" comes up a lot with Aunkai folks. It's sort of a shorthand for all the connection/internal/structure work that the exercises help to develop. Mabu/the cross/shintaijuku/spear thrusting all serve to develop the frame. I find that "frame" also comes with a lot less baggage than "internal skills", or "IT".
I actually like using kettle bells for some connection/frame training since almost all of the basic KB exercises pass movement through the core of the body out to the limbs and also reinforce dynamic balance.
Okay, yea..I have some experience with Ark and Rob and do some of their exercises when I can. Heck I can't do them without the weights so, no I haven't looked at adding them. Indian clubs though, I see lots of value there as they enforce alignment and posture and give you something to think about/control while maintaining the frame. they are only 1 lb a piece, but if you are doing frame type work like this, which is essentially the normal indian club workout, you will get a heck of a work out cause your frame is extended and the weight is very, very eccentric in nature hence even though it weighs 1lb...it sucks.