I know exactly how CAs work. I've built several.
Wosign does not issue a cert without an email verification.
You can look on their website. There's a nice big box to enter an email address to verify your domain and get the free cert.
Sorry -- "Let's Encrypt" with file verification is not DV.
It's just not DV. Simple really...
And it's gonna break the web. Like netlify up there a few post... using rackspace and "Let's Encrypt". ehh. The first few months will probably be fine and then everything is gonna tank.
Until the smart realize that ACME is fine -- as long as you remove the "or file verification" text.