Okay let me tell you how it works for me maybe that'll help you mparade (and I believe nev said it worked the same for him as well).
1080 ti, Win 10 x64, creator's update but not the fall thingy (not yet anyway), drivers are not the latest right now, 385.41 but I haven't found that to make a difference.
My main display is connected via displayport and doesn't even do 3d itself, I watch 3d films in my VR headset (Oculus Rift, connected via HDMI - but it doesn't seem to matter). All the 3d films will open in 3d by default, so on my display it obviously looks wrong - 2 distorted images side by side - but I mirror the desktop to my Oculus using Virtual Desktop and just have to activate the 3d mode within the application to get a perfect picture in the headset. I don't know if your TV would have something similar, to force enable 3d, but honestly I don't think it matters. madVR clearly doesn't care that my display doesn't do 3d, it still opens the 3d version when my VR headset is disconnected.
I do not install nvidia 3d drivers. Just the base drivers (+physx), not Geforce Experience, not the sound driver, not the 3d - I simply don't need those. I don't use the LAV/madVR built in MC (not much difference but I like to use MPC-BE sometimes so I always make a manual install of madVR/LAV and override the MC ones). I also don't tick the "enable 3d decoding" box in MC23, unnecessary in my case.
Of course when installing LAV I tick the box to download the extra 3d decoder. I'm using the 64bit version when playing back with MC23 and the 32bit version when playing back with MPC-BE. Both are installed at the same time and work fine.
In madVR all I had to do was : rendering, stereo 3d : enable stereo 3d playback (unticked the boxes below) and in devices "your display name" properties : 3D format : auto. I don't use profiles in madVR, I just have keyboard shortcuts to change the upscaling algorithms used etc. I so rarely need to change the refresh rate (99% of the content being 23.976/24fps in my case) that I just do it in Windows or nvidia CP.