Customizing group/about.html

In ckanext-scheming, the template group/about.html is located on templates/scheming/
The first line is "{% extends "group/about.html" %}"
And plugins.py contents " def about_template(self):
return 'scheming/group/about.html' "

This structure prevents another extension to extends group/about.html,
with the adviced method, I mean. (i.e. a file "my-ext/templates/group/about.html" whose first line is "{% ckan_extends %}")

WIth changing the scheming-extension code, it is possible to let my-ext to work. (if you want we could create a pull request)

Is there another solution ?
(with or without modifying scheming-ext)

Start with templates/scheming/group/about.html and the about_template entry point in plugins.py. Trace how the template extends group/about.html and how another extension's my-ext/templates/group/about.html is discovered. Done means the supported customization path is established and allows the described {% ckan_extends %} override, with any required documentation or code changes identified.

Written by the indexing model from the issue text.