Let's say you stepped out of Lucky 38 and haven't dealt with Benny yet. You'll be invited to Crooker's office. Can you take the NCR questline straight to the end without dealing with Benny? Or does the game stop you at some point and say "Remember what you came here to do?"?
I don't have a save at that point so I can't confirm myself. Can anyone try this or check the G.E.C.K for some info?