Use of UE4 in other Middleware

We are developer of middleware for procedural game content.
Our goal is to offer a low-level SDK/API for real-time content generation. Note that we are not a rendering company, but we would like to allow users to visualize procedural results with nice graphics. One option is to ship our engine without UE4 and allow the end user to integrate with their game. However, we expect to have to modify UE4 to interact with our SDK anyway, and game dev users would not know how to do that. A better choice is to ship our procedural middleware SDK with UE4 doing the render. Our question is how to use the standard EULA in this case. Are we responsible for the 5% royalties or is that up to the game developer? How do we transfer the UE4 EULA on to our end users if our SDK ships with UE4? How do we avoid ourselves and the game dev being charged the 5% royalty twice?


As far as I know you are not allowed to ship anything related to the editor source and editor tools other than forks through Epics GitHub.
For users to access GitHub they have to sign up with Epic themselves.
If you made your extension as a plugin/module it would be trivial for the end user to download UE4 and buy/install the plugin through the marketplace though.