Wait for custom script to exit before starting any game-related processes.

[caferen]

Is your feature request related to a problem? Please describe.
Games launch without waiting for custom start script to exit causing a portion of the script to incorrectly take effect.

Describe the solution you'd like
Wait for the start script to exit before starting to launch processes.

Describe alternatives you've considered
tried <command> && gamemoderun ... but this is not ergonomic and it's not possible to separate all such commands from the script.

Additional context