Here is a guide on how to use DX12 For higher framerates.
How To Use DX12 For Higher Framerates
2. Go to Tab “Game” and then click on “Clear Cached User Data” on the bottom of your screen. The game will close automatically.
3. Rightclick on Properties of Squad in your Game Library
4. Go To Launch Parameters and add “-dx12”
5. Start the game
Sometimes just using the graphics presets works ingame and then restarting the game applies them. Sometimes doing so before being in a match (main menu) crashes to desktop. Just avoid tweaking them too much. I got it stable by just being in DX11, setting a preset, clearing user data and then starting in dx12, first joining a match, then choosing a graphics preset, closing game and restarting. Avoids the graphics glitches and keeps the game stable. But this might vary from person to person unfortunately. No stability guarantee. Matches themselves though are stable and I haven´t crashed yet.
At least this works for me on my RYZEN 5800X and RTX3080. I had 55 to 72 CPU Bottlenecks with harsh input latency in dx11 in fallujah, with dx12 i can sustain 80 to 100 now which on my 144hz monitor is so much better. you can do the -dx12 commandline in Hell let loose, insurgency sandstorm, and other UE4 4.26+ titles and it helps even high end systems with eleviating cpu/memory, whatever drawcall blah blah issues. The side effect though is, shader compilation and frametimespikes, stutters might be harsher and a bit more common.
Insurgency, HLL etc though are rocksolid on dx12 and don´t crash for me, only Squad is unstable if you f*ck around with graphics settings too much.