The item tracking type is not used for any logic other than showing and hiding the serial lot tabs and enabling or disabling the serial lot entry areas on different forms.  Editing the HQMS_items_1 table ItemTrackingSID field to modify it incase of accidently putting the wrong tracking type is not a problem as long as the user has not entered any serial or lot numbers against the item.

The main issue is that the user manually enters an item and the ERP import process is enabled.  When serial or lot numbers are imported QES will not allow the user to change the tracking type from the user interface.  The user can

If a user has entered serial or lot numbers against that item then the ItemTrackingSID should not be changed without consulting Horizons Support. 

The ItemTrackingSID's are as follows
11001    None    
11002    Serial    
11003    Lot