whdload_quit_key
The option documentation is properly formatted yet
Summary: WHDLoad quit key Default: Example: 45
Use this option to register what key WHDLoad expects to quit the slave. When this option is set, trying to quit FS-UAE via menu, keyboard shortcuts, or desktop environment, FS-UAE will inject this keycode into the Amiga emulation and wait for the slave to quit.
This only works if the Amiga runs something like this after the slave quits:
uae-configuration SPC_QUIT 1
You can force FS-UAE to quit by pressing quit twice, rapidly.
For an overview of the valid raw key codes, please see http://whdload.de/docs/en/rawkey.html.
Source: https://github.com/FrodeSolheim/fs-uae/blob/master/docs/options/whdload_quit_key