the Tor manpage still states, that "the [sandbox] option is currently an experimental feature".

How 'experimental' is it with e. g. Debian Stretch and using the torproject repo? Give it a try, or wait some more time?

It most probably just works and you do not see any differences after enabling it but it depends on your specific torrc -- https://mastodon.social/@nusenu twitter: @nusenu_