THANK YOU for ncdu. I used it regularly and it saved me lots of ... bytes.
I am also a developer of https://datalad.org/ and thus a heavy user of https://git-annex.branchable.com and have lots of folders with git-annex repositories where I do not want to "[D]elete" a file but rather run a git-annex drop or better (can do through submodules as well) datalad drop -r command on that given path to drop the content but not remove the files (symlinks). Not sure if worthy for every ncdu user so thought to suggest it to make 'pluggable', e.g. make it so if --shortcut-x="CMD {}" is defined, then for keypress x, it would run CMD PATH thus replacing {} with the PATH selected in ncdu. Then I could define my own for dropping in .config/ncdu/config or alike.