I'm not convinced they are.
Believe me -- I'm very competitive in the marketplace, but if the certification lab agreed with their 20A maximum OCPD specification for a 10 module string, that should be the answer.
Personally, I think it's a moot point because they are a 120VAC output solution, and I don't =personally= think 120 volt microinverters or ACPV modules are competitive in the market place, but I'm very uncomfortable with electricians arguing with manufacturer installation instructions for a product that's been through a test lab.