Start GTA V Without Launcher
A small article on what I did to play GTA V without installing the 2019 september launcher (f'ing annoying of you Rockstar...).
First tell Steam it's already registered by registering this 32-bit dword key value via run > regedit.exe
^ NOTE: They sometimes update the launcher and you'll just add those as well. E.g. When they patched the offline bug, they released Launcher104115.
Then just add the parameter
-launchDirectlywithin steam itself to the GTA V startup options. This will avoid the popup from steam about really wanting to start with that parameter if you just edit the desktop shortcut instead:
URL: steam://rungameid/271590//-launchDirectly(use startup options instead).
I retrieved the launcher value name from installscript.vdf in the game directory (check this for the name you need to use and every time there's an update for installing/updating to a new launcher). The -launchDirectly parameter was noticed while doing some debugging because I thought I'd have to patch some bytes to get this rolling but luckily they provided an option. This makes things relatively simple.