Rekordbox 3.3.0 preferences>advanced>auto export feature

Hi as i am now moving my master datafile to an external HD to use on my other laptop (using data management to save to an external HD). which should i have the auto export feature set to ON or OFF? Both computers & the external HD contain same copies of my original music file. Please explain this feature.

Also if one of my laptops was to have my original music file removed (to free some space) would rekordbox still work showing all tracks by finding them on the external hd?

thanks

FRYER