Maybe you ask what happened to the idea and if we will see it in future versions of Krita?
Here another template, which seems to be more elaborate:
The following things belong together:
And here you can get also templates for making comic and manga panels, they belong to the Mojo Moo for comics bundle in an older revision:
Plus the gutter pens in one of the bundles from:
This wiki-page describes how to use the gutter pens/tools and belongs to the Mojo Moo for comics bundle: