There’s no official list because they were mostly for me when doing testing, no guarantee they can be used by anyone else, but for what’s worth there are 4 of them:
-basefolder which can be used to tell the DSL that the subfolder where stuff is saved is somewhere else (I use that in visual studio because I don’t want to download the game server inside my source code repository)
Ex: -basefolder D:\ConanDedicatedServerLauncher
-gamefolder which gives the name of the folder where the game is actually installed (the one that defaults to ConanExilesDedicatedServer inside the main folder), no idea if that works, not used in years.
-steamid and -steamidclient which can be used to override default 443030 and 440900 values used with SteamCMD to deploy the server and the mods, and which in theory could be used to deploy other games but they would have to use the exact file structure with the same stuff at the same place, so probably would not work.
The bottom line: You can use them, but that’s at your own risk, I’m not going to maintain or improve these because they are not part of the “public API” and don’t work well with other things, like the “auto start DSL on startup” does not know anything about the command line switches, and I’m not going to add some more complicated stuff to make it work 