Move thumbfast.conf to a proper place.

[cold-nagai]

The thumbfast.conf file is supposed to be placed in the script-opts directory.

Default settings are listed in thumbfast.conf, copy it to your mpv script-opts folder to customize.

— mp.options.read_options(options, "thumbfast")

— https://mpv.io/manual/master/#lua-scripting-on-update]]):~:text=script%2Dopts/identifier.conf