THFR-E4 — Biological Realization of QCRS in THFR: Intertheoretical Convergence with the General Theory of Observation and the Observer

In THFR, QCRS describes an internal mechanism of local reduction and formalization of the information-quantum basis, through which, in the process of observation, an accessible distinction of Primary Objectivity acquires a determinate observable form and subsequently enters into the formation of stable Secondary Objectivity. For different morphogroups, the boundaries of accessibility and the character of such formalization may differ; however, QCRS itself has an exclusively biological realization in THFR. This leaves a fundamental question: why does the physical organization that carries out observational formalization belong specifically to the biological class? Within THFR, this result receives a theoretical explanation through the general architecture of admissibility and stability. If QCRS is part of the same information-quantum basis that it formalizes, its realization must also be subject to the general conditions governing the selection of admissible configurations. The intersection of homeostatic and harmonic constraints defines the domain of stably realizable organizations within which the biological class of physical QCRS realization is formed. Independently of this construction, the General Theory of Observation and the Observer derives a criterion of subject and observer organization without a prior choice of biological, artificial, or any other class of physical realization. Its subsequent logical, critical, and cross-disciplinary validation shows that the entire positively established class of subject realizations remains biological. The present work establishes that these two results form an intertheoretical convergence at the level of the class of physical realization. THFR arrives at the exclusively biological class of physical QCRS realization from its own ontology of formalization and stability, whereas the General Theory independently arrives at the biological class of the observer from a criterion into which biologicality was not built in advance. The exclusively biological class of physical QCRS realization thereby receives not only an internal theoretical explanation, but also intertheoretical support independent in its premises, method, and evidence base. It is precisely this convergence that substantially strengthens the evidential status of the biological realization of QCRS.