Optional Package Cross Publisher Scenario - different publisher than Base Package

As stated here, Optional Packages should work with different publishers that the Base Package's one:

"Cross Publisher Scenarios
Taking this a step further the platform supports the ability for the optional package and base package to be from different publishers if you want to co-develop with other publishers. I want to high light that these are publishers that you trust and the base app controls what optional packages it works with as you are loading content/ code in proc."

The issue I'm facing is that when installing an Optional Package with a different publisher than the Base Package's, the next error shows up, even though the Base Package has the Optional Package correctly bound as a related set (no application inside, used just to specify it's publisher):
"A main app package is required to install this optional package. Install the main package first and try again (0x80003d12)"

If I use the same publisher, it works as expected.

What is causing this issue ? How can I use different publishers ? Is there some missing documentation, or this feature is not supported ?