Sorry, but idk the fixation for the unreal in a flight sim. It will break all addons to zero and also the people that begging all the time for Unrel maybe never played any game or sim in unreal or if do not picky or have. detailed view in many visual aspects. MSFS, DCS, Il2 BoX, P3D, XP12, Aerofly FS4 all very beautiful with the correct addons, all without the Unreal, so i not see any amazing advantage to jump to an Engine that have strong problems with performance. Infact of almost all of gaming engines it is the one that have worst performance for the same visual quality, also it tends to ugly do many popups in close distance shadows and many unreal games have problems with over lighting.
So changing to an overhyped engine thats only good for shooters and even for that exist better engines.
Unreal its only good to take some screenshots, if you see it in action, its slow, ugly popups, many times unrealistic lights and a hog to do updates because the games tend to be all in a single huge data files.
So let Unreal alone for the people that want to do close range view games and not want to deal with Unity neither have possibilities to have a proprietary or better engines. For some reason all the best flight sims are not in unreal engine....
Some times i feel that begging for unreal engine is like a religion where some guys want everything to be in unreal without any reasonable and rational explanation of the advantages over the cons.