[sidlls]

That "detail of implementation" is what is used by user code, e.g., `myError.As(...)` uses reflection, implicitly.

[Thaxll]

Then what? It has 0 performance impact, we're talking about error handling here, it's rare and not in hot path.

[sidlls]

It does not have 0 performance impact, it's not rare, and in applications that are in the hot path, error handling is also in the hot path.