If I might add, it is "possible" to use uMMU and the DGIV in Orbiter, as I understand it, it's the new surface on planets that makes uMMUs not usable on the ground, and the HUD that has changed too in Orbiter 2016, so when I use uMMU in Orbiter 2016, it's only in external view.
The DeltaGlider IV, it works until for some reason the radar altimeter will think you hit the ground but you're still a few kilometers high (happens close over the Moon's surface).
However the Arrow Freighter don't work at all (with me), I remember dgatsoulis made it work (but only for him as this is DanSteph work after all, so cannot share publicly unless DanSteph gives permission), tho DanSteph showed us he's working to make them all
compatible for Orbiter 2016 (as he did with OrbiterSound already), we just have to be patient.
But when it works, it's cool to fly the DGIV