BP, I am not familiar with Rotterdam other than as pax, but it's a serious airport with pro ATC who I would expect to advise of any conflicts between myself on a published approach and you on a DIY one. While not ideal, not the end of the world either.
But consider other scenarios, e.g. non-towered field, VRPs that start many miles out from the airport with the airport nowhere near in sight (Vienna, Malaga, etc) or transits (Barcelona, Perpignan just to give you two). In these kind of situations the last thing you need is someone calling a non-published VRP and no possible help from ATC.
Call me a stickler for procedure, but the vast majority of mid-airs happen in the vicinity of an airport - not a place to introduce ambiguity, at least in IMHO.