@Julusian, I can’t seem to be able to build Server so far. I’ve tried the entire week with different settings in VS2019 and I can’t get it to build. Do I need a particular VS version for building?
Scratch all that, I finally managed to build it! 
I also found out that 2.3.x versions changed the SEEK command values (frames vs. milliseconds?), which broke part of my workflow and get some playout quirks with RedCast OnTime.
I’m editing my post to tell that I managed to build @Julusian’s fork and after a bit of testing, the only thing that held back the build was screen-consumer's performance. It dropped/unsynced a lot of frames, but after I turned it off and worked with NDI only, no problem. Right here I have no Decklink for testing yet, but I don’t think it might pose any more trouble than NDI by itself.
Any test you need me to run @Julusian?