CUP isn't online compatible at all, and regarding HSFX see
https://www.sas1946.com/main/index.php/topic,44134.0.html, Reply #2
Beside that, we now have ~200 Missions on the Server (between 30 and 180 minutes long), all of them based on UP3 content and extensivly using MDS features such as RRR, Ressources and FoW. Storebror has fixed a lot of Bugs in UP3; he even introduced some 4.12 effects in his wonderful Patch Pack
Speaking only of Missions here, I suppose it would take the same amount of time to simply make them HSFX compatible as it took us to make them in first line .. plus we would lose lots of cool features and achievements that way...
Regarding Full-Real Options: Apart from View settings we are already "full-real". Those who want to fly absolutely full real always have the possibility to switch off icons, stay in the cockpit and only use navigation map (as most of our missions are coop style this won't be some kind of disadvantage for you) .. Also, we have been playing with FoW a bit, so on some newer missions the "normal" map will not help you as much as it used to do .. and, who knows what comes next...
Best Regards,
skylla