The spec today says that if e.g. copyTextureToTexture identifies a validation issue, the encoder merely becomes invalid, and only later a single validation error is generated in CommandEncoder.finish().

This means pushErrorScope/popErrorScope are unable to isolate or identify which call caused the error to occur.

I believe that calls should generate validation errors (for use with error scopes) normally, instead of being deferred. (but giving details about what caused the encoder to go invalid should totally also be an error that happens at CommandEncoder.finish() too)