I don't think it makes any difference. Your Reverb has also settings to increase Pixel Density.
Regarding your question, I don't know the exact technical details but I know the DLSS and Supersampling or pixel density are different techniques. They don't cancel each other.
DLSS smoothes the edges and reduces shimmering a lot, much better than MSAA at a fraction (huge smaller fraction) of performance cost. But DLSS introduces blurriness and goshting with can be alleviated with Supersampling.
This was my finding after months of frustration with MS Flight Simulator. Using DLSS alone was very underwhelming, so I was using DLAA but with worse overall performance. Until I tried Pixel Density (supersampling) 1.5-1.4 and DLSS on quality.
Exact same scenario applies to DCS and the combination of clarity, performance, soft edges and shimmering is the best I could get of all settings.
Now I settled with 1.3 Supersampling, DLSS quality, smooth filter 0.3 but I even could put shadows on high and it's gorgeous.