The main one:
• r_raytracedReflectionsTemporalUpscaleQuality 0 // Gets rid of the flickering in reflections as well as makes them overall more cleaner and less blurry. This one has a slight hit to performance, best used with DLSS, FSR, or XeSS based on your GPU vendor, because the reflections render based on your INTERNAL resolution. Consider keeping this setting unmodified if you're going for native resolutions.

The optional one:
• r_ssr 0 // Disables the game's screen-space reflections that blend over the ray traced ones. I normally HATE SSR, but because of how this game's RT reflections work, there's a lot less particles in the ray traced structure compared to Doom Eternal's raw RT reflections. Try toggling it on and off in certain shiny areas and see how you feel. I imagine this will be remedied once the full Path Tracing update arrives.

If you want to turn these commands on all at once, you can do the following

• Go to your DOOMTheDarkAges install folder
  
• Go into the base folder and make a new txt/cfg file
  
• Put each of the two commands in said text file ON DIFFERENT LINES, then save the file
  
• Launch the game, then in the console opened by pressing Tilde (`/~ key), type "exec x" without quotes, and with x = the txt/cfg file you just made WITH the file extension at the end!!
  
• You will need to re-execute the command(s) every time you launch the game and every time you make any changes to your video settings, so this makes it way easier. You can also press the up or down arrows on your keyboard in the console to cycle through the previous console commands you entered from the current session.

These don't pertain to raytracing at all, but you can put the following in your Steam launch options (without quotes!) for some benefits

"+com_skipIntroVideo 1" - Skips the startup logos completely, which helps with bootup times immensely
"+com_skipKeyPressOnLoadScreens 1" - Skips having to press space when a loading screen is finished, good for getting right back into the action, but if you appreciate the loading screen tips and pointers, perhaps ignore this one