The last line is the key one.
The DDG requirement is what is killing any chance to do that. Your manned FVL designs don't fit, whether tiltrotor- or blender-based.
That leaves you with other helicopters, none of which represent big improvements (I don't know why people have stuck on S-92...it's not that great), or various H-60 SLEPS. Adding 5-40KIAS and a little more lift isn't exactly game-changing. There's little reason to absorb the EXORBITANT cost of a new design (not just the aircraft--training, spares, manning, basing, etc.) unless there's a huge leap. So if you want a manned platform that's DDG compatible, it's various flavors of H-60 all the way down.
You could commit to a large UAS to replace the R. That's probably the real solution, but a VTOL UAS that large is a good amount of time and money away. Given competing priorities, that's a ways off.
Lastly, you could split the fleet and have a big-deck aircraft and DDG aircraft. If you're on the big deck, a navalized FLRAA (for example) would work great. You could put the "C" back in CSAR and reach a long ways from Mother. It could also hunt small surface threats a lot better than F-18s.