Thank you to @thoka and @pfaffman for your time and replies.
I’ve since performed the git restore.
As Jay’s pointed out that people generally don’t use custom certificates anymore, I suppose at this time I don’t see a burning need for it either.
I did another ./launcher rebuild app and the launcher ran without issue.
As an aside I simply input the cloudflare template at the bottom of app.yml as directed, but launcher came up with a syntax error. I removed it and all is fine. I never experienced an issue using Cloudflare without the cloudflare template so I’ll just carry on.