"request crossing clearance VFR, but can accept IFR if this is helpful to you". I use variations on that wording quite often, where it looks like I can make the controller's life easier
I've always thought you were making a controllers life easier by being VFR, as with IFR there are greater spacing requirements between IFR and other traffic, and they would have to work harder to pass traffic information and provide spacing, whereas VFR there aren't the same required minimum lateral/altitude requirements??