How to stop UE4 editor auto-starting SteamVR?

As far as I can tell, the only answer is "hahahahahahaha". There doesn't seem to be any setting or way to do this, short of flat-out uninstalling SteamVR (which, obviously, is not a solution. It's like curing someone's cough by shooting them.) This is a massive oversight, and badly needs to be fixed. I'm honestly shocked that it hasn't already been.

For me, it's a problem because SteamVR doesn't automatically, on an application startup, redirect sound made by that VR app to the VR headset. Sure, that's shitty coding or design on SteamVR's part, but they at least have a very easy workaround: You can have SteamVR, on startup, redirect all your computer's sound to the VR headset. (This may even be the default; I could well have changed the setting at some point.) Now, normally, this is fine -- after all, I only start SteamVR shortly before, you know, playing VR. Then I started toying with Unreal, and before they brought up any project menu, before any settings were displayed, before any interaction short of using Task Manager or sigkill to end the process was possible, it started booting SteamVR. Invisibly. I'll let everyone reading this figure out for themselves precisely why this is not a good thing. (Hint: If your sound is redirected somewhere else, what do you hear on the old output?)

Long story short, it's a massive oversight in UE4 that somehow managed to be allowed into the final product. There's no workaround aside from manually fixing the issue every single time.

@nic-hartley cool story bro. Answer is below and this is duplicate of #441149