Aye. So obvious, but not for my small brain, apparently. Thank you!
EDIT: New GZDOOM version is giving me a problem with the aspect ratio and whatnot, showing an ugly green texture around the HUD at the bottom of the screen and slightly altering the AR, but only after I exit the menu. Looks like I am going to have to sacrifice WadSmoosh if it means I get to play a DOOM that doesn't have any weird graphical issues. I'll see if I can find another way to get all of DOOM and the SIGIL WADs to be launched from a single executable.
Worse case scenario, I'll just make an icon for my desktop that just opens the folder.
