Is it planned to add dlss features to UE4? I couldnt find any information at all abut this topic. Ive seen some videos online, where people added dlss to ue4 developed projects, does someone have any information about how to do it?
No, because DLSS does not “just work” 
The way it work is you submit the game to nvidia and they using there machine train neural network model using machine learning by running game in 4K. They train the network how you game should look like in 4K and which later DLSS use to upscale the game based from that model and that model is distributed by NVidia with driver update (if im not mistaken).
This model can not be done for whole UE4, because UE4 alone does no proper game design that machine learning can target, nvidia can not predict that in any way if the game is not done. So regardless, you need to have a ready game to be submitted to Nvidia first, i dont knwo how but there reddit post i found that gives hints:
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Looking it seems it’s nvidia game works feature, so you should llook at game works plugins if anything
yeah makes sense, I knew it was supposed to be trained, but I didnt know much about the workflow, I thought we could simpy train it in a similar way like light building in Ue4 personally, good to know though, thanks for the tip. I still think for Archviz and stuff it could be trained in a way similar to Nvidia Spade or some specific game styles so that we could basically select a pretrained style similar to luts. Its just imagination though, thanks for the info anyway.
Styles? That in deed sounds like interesting idea, but this is something NVidia needs to implement