One thing that seems very lacking in DiligentEngine are concrete and useful examples on how to use it. Lack of documentation is fine, because the code can help with such and AI agents can also help with that, but having concrete examples on how to use the library are immensely useful for someone trying to get this running.

For example, NVIDIA Donut has a kitchen-sink type of sample with all the common graphics features included:
https://github.com/NVIDIA-RTX/Donut-Samples/tree/main/feature_demo

That's a great way of knowing what the framework is capable of, and makes it much more useful.

Or this book, which has a whole modern scene showcasing all techniques learned in the book: https://github.com/PacktPublishing/3D-Graphics-Rendering-Cookbook-Second-Edition

Or even old Irrlicht: https://irrlicht.sourceforge.io/docu/pages.html