Sorry for the delay in replying. I found a rather interesting Puella Magi Madoka Magica fanfiction that I'm reading while on break at work, which leaves a lot less time for replying to the forums.

It's a doorstopping 590,000 words, but it's also a great read.
Anyhow, until 2.1.04, this is how I ran Elite: Dangerous Horizons.
1) Booted up my computer. (I turn it off while at work.)
2) Ran the non-Steam version of Elite: Dangerous Horizons
3) Had fun.
EDH would NOT load the full SteamVR suite of programs, just a few of them, which would allow the headset to work perfectly. No fancy tricks, no special settings, just simply not loading SteamVR first.
Unfortunately, this isn't true in 2.1.04 anymore. EDH does load the full SteamVR suite, which is
extremely annoying. Because when the full SteamVR suite is running, the graphics look worse. Aliasing artifacts are worse, the scale is off slightly, and the text is harder to read. There isn't a targetRender setting that clears up the text AND doesn't leave me nauseous after an hour, and I prefer to leave the HUD set to default.
Way back in Engineers Beta3 (IIRC), I rated the Elite VR experience as a 10, where 10 is "The Lab" quality. I tried Elite at the time with SteamVR running, I'd say it was rated a 3 at the time. At least you had head tracking.
Engineers Beta4 improved the VR experience for many people, but I had to rate it a 9. Still great, but not as good as it could be.
2.1.04 doesn't allow me to run Elite without automatically running the full SteamVR suite anymore, I have to down grade it to an 8. Still better with VR than without, but little things like scale and having to lean towards the text to read it is annoying.
I just hope my VR experience doesn't go down any farther. I'm tempted to kill whatever processes I don't need to run the headset properly, but I'm a bit cautious about tempting fate.