Experimental research note This manuscript presents an experimental theoretical framework currently under active development.The concepts, terminology, and variable definitions are still being consolidated, and version consistency across related manuscripts has not yet been fully standardized. The present document integrates elements from a prior theoretical note and several tumor-specific analyses.It is released here for transparency and early documentation of the conceptual development process. This version should therefore be regarded as a working research manuscript, not a finalized publication.Subsequent versions may revise terminology, parameters, and structural definitions as the framework evolves. Version 5.0 extends the threshold principle introduced in Version 4.0 by defining Integrated Effective Pressure (EPI) as a quantitative representation of cumulative effective therapeutic burden after accounting for microenvironmental attenuation. Using a distributional interpretation and a simplified mixture hazard structure, this framework explains recurrent dissociation between objective response rate (ORR) and overall survival (OS) observed in resistant solid tumors, with representative reference to phase III pancreatic ductal adenocarcinoma trials. The document presents structural consistency analysis, illustrative quantitative reconstruction of hazard behavior, and threshold-based interpretation of survival transition. This work represents an evolutionary extension of the Spatiotemporal Coordination Framework and is intended as a theoretical and hypothesis-generating model rather than a definitive predictive tool.