BTW like @Heliosurge noted, you can actually bypass the piplay sofware. I do this a lot myself because I only use SteamVR mode and I never change HMD properties and just like you I don't like 'piplay' at all. So in that case, make sure all your piplay execs are down (piplay.exe piservice.exe and piserver.exe) and then just start piservice.exe. This is the executable that that SteamVR drivers communicates with (and this communicates also with piserver.exe which communicates with piplay.exe, but only if those are up and running). So if you just run piservice.exe then steamVR communicates with that and you're good to go.
So what I do is make sure the HMD is in steamvr mode, that my properties are like the way I want them to be (resolution etc). I then ensure that none of the services actually autostart in windows and that piplay.exe also doesn't auto start. Then I have a link to piservice.exe on my desktop. So when I start my PC, I just click that shortclick to piservice.exe and then I can run SteamVR. This smooths out the process a bit. And it has the added advantage that you can easily see in the piservice.exe ms-dos output if something went wrong. It's a bit hackerish though
Then again, also like @Heliosurge noted, I'm not even sure if it still works like this in the latest version. I'm still on v1.1.92 myself. I never liked V2.x with the custom Pimax HMD renderer, I still think the SteamVR renderer is superior. Anyway, this used to work on V2.x too like this but I haven't tried v2.x for the last few months.