We can do from RSA1. Secondly, there are no standard steps to un check them. These flags will only help you if you do reporting on top of DSOs directly. Otherwise, this does not make any sense, in fact these SIDs will hamper the loading performance.
Unchecking BEx flags will not delete the SID tables which were created so far your DSOs. This will not create SIDs further. Actua;;y, if you are no reporting on DSOs, i suggest you to uncheck SIDs.