the usecase is that if our administrator needs to change some configuration settings which may impact current login users, the idea is to perhaps have a mechanism for force a relogin so the setting takes affect. I accomplish by writing a cmdline application and querying the phabricator_session table to invalidate the user's session, it's not integrated into the phabricator UI, but work good enough for now.

Which settings, in particular, are you seeing issues with? The correct answer is to fix them, not hack in something to work around them being broken.

This has been implemented in the meantime:

./bin/auth revoke --type session --from @user