why would I do it outside of kakoune? kakground allows you to select a directory and dynamically change backgrounds asyncronously just navigate the buffer and the line you where you stand will be set as the new background
kakgroundtakes one param, the directory with the backgrounds from whichi you will choose and it prints them in a new buffer with the hooks needed to easily change backgrounds
kakgroundprovides an option to define the command used to change the wallpaper, for sway users you would like to use something like 'xargs -n 1 -I {} swaymsg output "*" background {} fill', the default option would work for any system using feh, but the logic is the same, the file es piped to the command, thus the use ofxargs