https://docs.libretro.com/guides/overrides/
Per Core Override
/config/<name-of-core>/name-of-core.cfg (This path is set under Settings -> Directory -> Config)
These settings files are created from the Quick Menu -> Save Core Overrides option and contain ANY (supported) settings you have changed since loading content. These settings will be loaded every time you load content with that core.
Per Content Directory Override
/config/<name-of-core>/name-of-content-directory.cfg (located with per core override)
These settings files are created as above with the Quick Menu -> Save Content Directory Overrides. The settings will take precedence over name-of-core.cfg
I do not want to have to do a per game override.
Yes IT WOKS
\\centipede\configs\all\retroarch\config\MAME 2003 (0.78)
spinner.cfg
Now the spinner will be used for roms directly in spinner dir