No impact if you are reading this DSO.
By switching off the SID generation, you are saving time in data load, as most of the time has been taken for generation of SID only, which is used for reporting as BEX works in SID.
Where as the other parameter, basically we read the active table in case of look up) will be as it is, so there is no worry as far as look up is concern.
Thank-You.
Regards,
VB