Thanks for the suggestion, @balloon ! As Luke mentioned, using Cloudflare to front to our services has tons of problems (the ones that started this post, and more general descriptions of the higher level problems here: [Support Guide] Why not proxy to Netlify?). Since this isn’t a use pattern we can support for our CDN, I don’t think we’ll probably write code to enable the unsupported setup to incorporate lets encrypt SSL - we already provide SSL at the netlify hostname which you can tell cloudflare to connect to directly :)).
If you want to use Cloudflare, please do! It’s a great service! It just doesn’t work well in proxy mode with our CDN, so we won’t try to imply that it might work well by working around configurations that currently make it obvious to the end-user that this is not a good setup.