Shape Keys → integration of Relative & Absolute (Non-Relative) features on the same mesh Object

Riggers and Animators often need more and better organic control over morphs and mesh deformations;

Sometimes, the simple combination of different Relative Shape Keys to form, for example, a facial expression —combining an eyebrows' Shape Key with a mouth's Shape Key from the same mesh Object— is not organic enough. What would be needed is that, INSIDE the Relative Shape Keys (example: "Basis" to "Key 1"), there would be a possibility of making an inner (sort of) "group" of Time sequenced Absolute Shape Keys, so that the Relative morph from "Basis" to "Key 1" (or the inverse, "Key 1" to "Basis") actually follows a sequence of precisely sculpted/modelled morphs (as it works on Absolute Shape Keys), so that actually what we'd get as morphs would be something rich and complex such as the following: "Basis" → "[Key 1a]" → "[Key 1b]" → "[Key 1c]" → "Key 1"; AND, extraordinarily, we would also be able to combine any of that inner-group morph state (exemple: "[Key 1b") with any other number of different Shape Keys (as we do naturally with Relative with facial rigs); and, of course, any of those other "Relative Shape Keys" could also have own "inner group" of "Absolute Shape Keys".

In conclusion, the integration of Relative & Absolute states for a single mesh Object, seems to me a revolution in Shape Keys in Blender, from a Rigger/Animator's perspective.

I've just recently discovered the Absolute state for Shape Keys, and that was all that I needed from the start… but, then, I've realized that, for a single mesh Object, ¡¡if I use Absolute, I can't use Relative!!, and ¡¡if I use Relative, I can't use Absolute!! But I needed both, for a more organic workflow.

Thank you.