The incoming version 4 of prepar3d will need a new module from Pete Dowson.
His FSUIPC tool is a pure 32bit mode that is not compatible with the 64bit architecture of P3D v4. So there will be a new module FSUIPC 5, not an upgrade from FSUIPC 4, and it needs time to be coded so it shouldn’t be ready on the release date of the flight sim.