There was a feature request earlier this year to add DLSS back then DLSS really only helped in situations where a game was GPU bound, as DLSS improves performance by lowering the resolution and then using AI to fill in the blanks to make it look close to the native resolution (at least, that's how I understand it, I could be wrong) so, given that it wouldn't help much, in Arma 3, which is CPU bound most of the time, the request was justifiably denied.
In their keynote today Nvidia announced DLSS 3.0, which apparently also increases performance in CPU-bound scenarios.
I pulled one quote from Nvidia's DLSS 3.0 news page (https://www.nvidia.com/en-us/geforce/news/dlss3-ai-powered-neural-graphics-innovations/), that seems relevant
NVIDIA DLSS 3 Can Double CPU Bound Performance
DLSS Frame Generation executes as a post-process on the GPU, allowing the AI network to boost frame rates even when the game is bottlenecked by the CPU. For CPU-limited games, such as those that are physics-heavy or involve large worlds, DLSS 3 allows GeForce RTX 40 Series graphics cards to render at up to twice the frame rate over what the CPU is able to compute. In Microsoft Flight Simulator for example, with the 1:1 real-world recreation of our planet, DLSS 3 boosts FPS by up to 2X.
Arma 3 is a great game, it's by far the one I have the most hours in, I've seen this game come so far since I first played it in 2013, the one thing that has held it back, in my opinion, is performance.
I believe that DLSS 3.0 (if it functions as advertised) would be a great addition to the game.
The earlier feature request provided some resources that might be useful for implementing DLSS in Arma 3, so I figured I would link that here in case you might be interested https://feedback.bistudio.com/T163936
Thank You for taking the time to read my request.