Hello @AntonioJR,
The feature of getting separated layers from Model and Set/Background it was already on my list, but as you requested it, I thought it could be a good idea to start putting it into practice and see if it would work as desired. Here is a little video about it:
Credits:
“Wooden Chair” by Megascans
Music: It All Begins Here by Borrtex - Artlist
About the HDRI Scene/Bg, not so sure about this yet, indeed the management of HDRI seems still quite complicated, and even if I gave this as done, when updating the project from UE5 Preview 2 to UE5 release, I got some unexpected results that I am still trying to work around.
In any case, it is not a target feature to have a HDRI background (visible to camera) as it is in, for example, automotive tools. I might get the “total” solution for HDRI management but this is for sure a long term goal that probably won’t happen in the first release of Republic-RT. My goal for HDRI implementation, by now, it is to emit light and render reflections, as anybody could expect, and be able to rotate and switch between them in real time, which is actually working already but still not in a very efficient way.
I do prefer to explore the chance of implementing a sub-level (any user created level or from Marketplace) so characters or props can be viewed and light/rendered inside a context, using for the set the Directional light, HDRI and fog, and beauty light the model with the 3 Rect lights.
Thank you for your interest in the tool 
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*Big thanks also to William Faucher, for his excellent tutorials, specially, in this case, the one that has teach me how to setup these Stencil/Render Layers 
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