I'm not aware of any large-scale A/B tests for this. That being said, I imagine if Amazon thinks OV is good enough for them, I think it's safe to say it won't a

I'm not aware of any large-scale A/B tests for this. That being said, I imagine if Amazon thinks OV is good enough for them, I think it's safe to say it won't affect conversion rates all that much. Perhaps it would even have a negative impact, given that some browsers enforce OCSP for EV certificates, which could slow things down if the server or client does not support OCSP stapling. (Not sure if that combination - enforcing OCSP for EV but not supporting stapling - exists in a browser out there.)