Expression selector 'thisComp' resolves to master property composition instead of text layer composition in V8 engine

Migration Goal

Migrate a project that uses text layer expression selectors with master properties to the V8 JavaScript engine without breaking existing compositions.

Constraints and Uncertainty

The project relies on expression selectors that reference thisComp to access the containing composition's name or properties. In the legacy ExtendScript engine, thisComp inside an expression selector consistently resolves to the composition that contains the text layer. After switching to the V8 engine (default since After Effects 16.0), the same expression selector returns the composition of the master property instance when the text layer is used via master properties in other compositions. This behavior is not explicitly documented for the V8 engine and may vary between point releases (e.g., 23.x vs 24.x). The project setting expressionEngine applies globally; there is no per-expression override. The legacy engine is deprecated and disables multi-threaded evaluation.

Open Questions

1. Is there a documented specification for thisComp binding in expression selectors under the V8 engine when master properties are involved?
2. Can the expression be rewritten to reliably reference the text layer's host composition regardless of master property context?
3. Does Adobe provide a migration path or compatibility mode that preserves the legacy thisComp behavior for expression selectors?