That would mean an extension would have to mimick so much behaviour.
So if an extension adds a setting to a forum's settings, it has to create a forum list or select.
So if an extension adds a permission, it has to mimick all permission options (per user, group, forum, etc).
I am not sure if you know what you're asking for extension developers to do.
And it would still not make sense after that.
Cause if one of those settings relies or overrides a default setting, the admin still ends up searching all over the acp to find why his default setting is not working. As the overriding / relying setting is not immediatly below it.
I paid my two cents, but I'll do so again.
Developers should write a comprehensive list of settings.
Admins should read carefully the said list.
Possibly add a 'details' option in the extension list.