There is no GBA Retroarch emulator folder, and even if there was I doubt that would work since they are different emulators.
I tried doing the same thing you mentioned in the .cfg file for gpsp but it messes with the games and they fail to load. It would just be nice if every save file went into a nice folder without having to manually change the settings for individual emulators.
Necessary and Functional
These cookies are placed to make it possible to analyze this website (with Google Analytics) and optimize for the purpose of a.o. the usability.
Cookie names: _ga, _gat, _gid
These cookies are placed to show advertisements (of Google AdSense) and to get these close to your interest.
Cookie names: id, IDE, FLC, DSID, SNID, NID
These cookies are required to show the cookie notification bar, remember your cookie acceptance choice and apply this choice.
Cookie names: privacy_embeds, wpca_consent, woocommerce_cart_hash, woocommerce_items_in_cart, wp_woocommerce_session_, wp-settings-1, wp-settings-time-1