For anyone else looking for this, on Mint linux 20.3, the full path is:
/home/your_user_name/.config/strawberry/strawberry.conf
(.config is hidden, so use CTRL-H to see it)
@cherrystraw I can't speak to the program coding involved, but a new DB field (possibly in playlist_items ?) would get the ball rolling...although I'm certainly not telling Jonas anything he doesn't already know.