How can I force backup SSL edge certificates to be generated for my domains?
Some of them don’t currently have backup certificates.
I am unaware if we can “force” it 
Rather, on the next renewal of the Universal SSL, the Backup SSL should be issued.
Or somewhere in the meantime it will be.
If Cloudflare is providing authoritative DNS for your domain, Cloudflare will issue a backup Universal SSL certificate for every standard Universal certificate issued.
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