Epson 5040ub and Kodi

I am sure been asked before but not having luck finding info.

I have an Intel NUC that can display 4k content. It goes from NUC to Denon AVR-X6200 then to my Epson 5040ub projector. All are HDMI 2.0 and HDCP 2.2.

So I just got this new projector so looking at how best to setup Kodi and the projector. Since in past I couldn’t do 4k content I have limited content and knowledge as to how would be best to setup.

I know the projector can upscale all to 4K. Right now inside Kodi I have it setup display GUI @ 1920x1080p but projector always shows at 4K. When I play any movie it is always at 4K. Wouldn’t it be best to display at true res? I do have the setting adjust display refresh rate set to start/stop. Now when I play TV Shows the res seems to match the file. The projector changes the res.

So I guess it’s hard for me to know if the playing content is in 4k or just upscale. I have one movie (The Revenant) I know is UHD but since always playing at 4K I am not sure if getting true or upscale.

Any if this Epson and Kodi that can share/help settings that would be GREAT!