@Jeffro The second ... [reason] playing middle man between commercial themes/plugins and customers does not work [is] ... it doesn’t appear that the WordPress.org repository will list commercial plugins.

It's going to be pretty basic, that the plugin cannot be overtly commercial, itself.

Not and gain entry to the WordPress.org repository ... which success will require.

Really, the plugin has to be available on the Official repository. Otherwise, hey ...

So, get the commercial functionality out of the plugin, and do it elsewhere.

Get the plugin on the Repo, as a neutral interface, to allow discovery.

People know better than to mess with plugins that can't be on the Repo.
=====

We have a clear & dramatic precedent for the role of the Repository, in the Linux/Debian/Ubuntu world. 'Everything' is in the Repo. Everything, that is, that ordinary people & customers should be messing with. There are only a few, narrow contexts in which it is "responsible" to get stuff outside the repository.

[Guess where Apple/Firefox got the repo idea ... ]

Once the repository-paradigm became established, then it quickly became pragmatic reality, that anything that can't get into the repository is, 'by definition', bad news.

Once it's a Repo-World, there are reasons for things not being in the repo ... and they ain't pretty. There is plainly a positive-feedback effect that reinforces & drives an 'in-repo-ok', 'not-repo-bad' effect.

The "execution" of this idea needs to be modified, so as to allow the plugin to be hosted on the official WordPress.org repository.

Otherwise, the product is not only missing out -- it's actually 'suspect goods'.