Hi Mulla,
Since MBEW contains Material Valuation data SNAPSHOT (it doesnt store history), I dont think you can DELTA enable this generic Extractor. If you want Delta, (based on Monthly Updates), u can create a generic extractor on MBEWH which gives monthly data in table (whenever there are changes to a Material).
So, I think your load if you use MBEW should be a Full load to DSO and Delta to Cube. So, no need to Delta enable the Generic DS.
Regards,
Nag Vadlamani