Some would say it's "not intrinsic". The best evidence that it isn't is probably that isotopes would have been a forced answer that someone else would have come up with. (Or at least when I designed them, that they would go "oh... right... that's the answer!")
But I am mostly convinced that if you are looking for a Rebol-shaped-answer to non-value signaling states, you should be using the return value. Leverage the existing value-space as the "API"... just values in another form which can be "lifted" and "unlifted" through states when reflection is needed.
https://rebol.metaeducation.com/t/which-antiforms-are-in-use/2276
They're a frighteningly efficient answer to a complex question, that is built on a single "lift byte" per cell.
Regarding the "intrinsicness", I asked: "If Red Asked AI For Help, Would It Reinvent Isotopes?", @chatgpt said:
I'm interested to see what future AI say. But the sheer mechanics and design of Ren-C cells and stubs... with the out-of-band-of-leading-UTF-8 BASE_BYTE, the LIFT_BYTE, the HEART_BYTE, and the remaining flags fitting in 32 bits... I think I'll get the respect that has seemed hard to come by so far from all but a few of you.