Node sub-paths have no Page manager control

Problem/Motivation

Node sub-paths have no page manager context and make layouts a bit difficult. Simply, node/%node/%some_path pages that do not display in an admin theme, have no layout since they are not technically node/%node and Page Manager doesn’t kick in.

Clearly this may be a specific use case, but I do run into it regularly when building with Panels Everywhere. I prefer to not place page title and tabs in the Site Template, but rather place those items on Node, Term, or other page layouts. I first ran into this using Webform, but as we create other custom pages at node/%node/%some_path, it also occurs. I’ll describe it with Webform since it is a commonly used module.

How to recreate the situation using Webform as an example

1. Enable Panels Everywhere, Webform, and all dependencies.
2. In Appearance settings, disable “Use the administration theme when editing or creating content”
3. Use a Panels Everywhere theme that does not place anything in the page.tpl.php such as Versatile
4. Use a Site Template variant that only places Page Header and Page Content panes
5. Enable the Node template and add Page Title, Page Tabs, and Node content panes to the display
6. Create a Webform node and view it. Everything looks good so far.
7. Click Webform tab. We no longer have access to page tabs because we are no longer using the Node view variant.

Proposed resolution

I’m wondering if it would make sense for pages at node/%node/%some_path to inherit the settings from node/%node or if there could be a default page for node/%node/%some_path where variants could be created based on the %some_path string?

There are certainly ways to work around this like introducing the Tabs pane or Page Navigation pane at the Site Template level with visibility settings to only show where needed, but I do find that we run into this often enough that there could be a generic solution.