Hey Joe....

My two cents are that what is documented in the owners manual and in dealership/manufacturer workshop specs is 5 whatever quarts of oil into the engine when changed with a filter on the VX. What this guy you were talking to says is just that, talk, it's verbal and holds no accountability if something goes wrong if you were to throw 6 quarts in. Especially when the printed word says differently.
As far as the OEM filter goes, that has to be a load of doggy doo. I mean if after-market filters would cause problems to a VX, then I am sure those after-market manufacturers would not be advertising theirs to go into a VX.
All in all, my opinion, this dude you talked to is misinformed, uneducated and not equipped to hold his job. Quite frankly I see that a lot when at the dealership talking to any service manager. They are just that, managers, and don't have the hands-on experience or knowledge of cars to make such claims.
That's all I have to say about that.