Considering many webcomic creators care about keeping comics online and in digital format strictly, i doubt something like that is used.
Originally, templates like that were used for traditional comics/manga pages that were going into print, and required sections for trim, bleeds, and safe areas.
Personally, I don't use that specifically, but I always reserve space for trim, bleed, and whatever I want to be protected if or when I put my comic into print.
In reference to your quote saying it makes you feel like a real comic artist, I think that's great of you! It's good into getting into the technical aspects of things that are fun for you. Have a nice day!