There is no traditional media (cellulose, syn, or a combo) that is capable of separating fuel from other petroleum products.
IOW - a filter cannot distinguish the difference between gas and oil, hence it cannot separate gas from oil.
No - a BP filter won't help remove fuel dilution.
As for the ROI topic, a BP filter won't help there if the limit of 10k miles is the established constraint. Generally BP filtration cannot affect the wear rates enough in lower mileage OCIs, and therefore they never pay for themselves. You have to get out well past 15k miles before a BP even has a hope of paying for itself. In fact, there's no data I'm aware of that truly establishes the payback point in terms of a ROI that is, as a whole, consumable for all situations.
BP filtration, first and foremost, is a tool to extend the OCIs. It's a fiscal savings tool to reduce the number of oil changes. It is not a tool to alter wear; that's a VERY common misunderstanding and misinterpretation of several filter "studies". Any engine (or tranny, diff, etc) will have a wear rate of "x", "y", or "z" for each metal. As long as your wear rates are low, the oil is acceptable for continued use. There are condemnation limits for total magnitudes established by several leading diesel companies, but none that I've seen for gas engines. And, wear rates are never discussed by those same companies.
It is impossible for a BP filter system to pay for itself in 10k mile OCIs on a small sump system such as most any typical car/truck.