You're asking the wrong people. Revenue management decisions are made by the hotel, not Hilton Corporate or Hilton Honors. The only people that can say "yes" are those at the hotel. That's one of the quirks about the franchise business model used by hotel chains.

The best way to accomplish this would be to book a cancellable 3-night cash reservation and then contact the hotel directly and ask if they will allow you to pay one night with points. Make sure you understand what SK ARR is saying, to avoid disappointment about not earning points on the cash nights.