The STF is a scalar-response framework. Its field couples to the rate of curvature change — not curvature magnitude — and switches off entirely in a static spacetime. Every quantity in it is a theorem, a derivation, a declared architecture parameter, an external measured input named as such, or the framework’s one free scale, each carrying its stated status. Stability is a requirement on any completion, established on the backgrounds where the predictions are tested and open in general (Step 1 IV below).
Every paper on this site follows from the Lagrangian and the quantities above — as functions of the free scale, not of a fixed value for it.