Observed
We compile an InternalsVisibleTo grant into Unity.Pipeline.Editor and Unity.Pipeline (through an .asmref) to reach SerializedPropertyConverter, TypeResolver, PipelineTestRunner and TestExecutionResponse. Any release can change them without a changelog entry and break our compile.
There are also two types named SerializedPropertyConverter, in Commands/Scripts and Commands/GameObjects. Only the first is behind set_serialized_field.
ExpectedFixes for U-02 and U-07 remove our need for these. If not, a public API for a test run with structured results, and for SerializedProperty ↔ JSON conversion.