Hosts running battleye will automatically kick connected players who are not running battleye. There should be a way to view if a player (host in most cases) is running battleye in Stand itself through Players/{specific player}/Information/Status and in LUA scripts running through Stand with something like players.has_battleye_enabled(pid)
Unfortunately there's no way to really tell the difference since a Stand User as host is also running BEServer with the difference being they won't kick anyone.
Hosts running battleye will automatically kick connected players who are not running battleye. There should be a way to view if a player (host in most cases) is running battleye in Stand itself through Players/{specific player}/Information/Status and in LUA scripts running through Stand with something like players.has_battleye_enabled(pid)