Top nav of their site has an "API" link which goes to a page that says "ELV’s API keeps your email list clean. Notify website user about an invalid email address when they are filling out a form."
So presumably yes
So presumably yes
I’d look into fingerprinting (https://github.com/fingerprintjs/fingerprintjs), block by ASN if it makes sense for your business (does OVH really need access to my SaaS?), use an active disposable email checker and possibly flag risky orders for manual payment capture if at all possible.