IMHO, this is such an easy app to use and set up that you don't need any guide. I'd never sat down and used Let'sEncrypt (as I could never clear off something like a week to read the thread and play with setting it up), but I got this all going within 5 minutes, with no thought involved. But, if you need subfolders and not subdomains then you've got to manually edit the nginx configs. Myself, I'm just using subdomains. But, for advanced features that you may or may not require (I don't for my use case), then this may not be for you.
That, and if you've already spent the time and aggravation setting up LE, why switch?