Accepting that that might be the case........in your view where does IP/IS fit in the aiki paradigm or does it?
I don't really know how to answer since I haven't seen a definition of IP/IS. I also think that the founder used "Aiki" in wide variety of meanings (e.g. Aiki Budo - a prewar name of his art, Aiki as moving out of the way, Aiki as being solid, etc...) and an attempt to fit that "Aiki"
into an "aiki paradigm"
seems to me an unnatural one.
One can ask "How important was the 'Tenryu ability' to the founder and in the way he saw his art" - my guess is that not very, but I am nowhere near even trying to prove this.