Medically there may or there may not be a difference but in my experience the authorities insist on seeing the words and terms as prescribed in the entry requirements.
best to check the website of the Ambassy. I think they do issue O visas. And ones does need medical insurance anyway, regardless of the type of visa, to apply for the COE. Plus insurance for COVID treatment (this may be explicitly included in the regular medical insurance certificate, if not , a separate one is required).