So I can't answer this directly, but I can speak to the extent to which I've validated the use of Oculus Avatars outside of their definition of "cross-platform." (i.e. OpenVR)
Since you're ultimately running on an Android device, the .aars you need to run the Avatar SDK will still build correctly in your project. I think you might even be able to plug in user-specific User IDs at runtime and they will load up correctly, but I was anticipating having the use the static set of 12 avatars that they stipulate for use in cross-platform integration.
I have put the Avatars SDK (and just the Avatars SDK, as of v1.5) into a virgin Unity project, plugged in a User ID, and saw it load up correctly. Just a Third Person instance, sitting in front of a stock MainCamera.
I haven't gotten as far as remotely piping some pose packets into it yet to see if it moves. But, within that limited validation, it works.
Big caveat: my test device was a Galaxy S8, which you can probably consider an ambiguous data point, since it is both a GearVR device and a Daydream device. I can't say what would happen if you did the same with an S7 or below, or a Pixel.
It's a back burner ticket at the office so I can update you as I learn more about this.
Looking back on our development history, we have anecdotal evidence to suggest that multiplayer builds of our app fail when trying to call Platform or Avatar SDK stuff on a Pixel. We were doing flat (non-VR) builds of our app on Galaxy S devices and that we would see the other networked Avatars moving around, but not on non-Galaxy S (i.e. GearVR-compatible) devices.
Following. We'd really like to display Oculus avatars on plain ol' mobile screens -- not even in a headset. Being able to build the avatar package into generic Unity Android would be super super helpful.
Hey Ross ... any update on this? We're trying to plan for some releases later this summer, and need to make a decision on whether to integrate a third party avatar system. Any hints for us as to when the "good old 2d phone" functionality might be available?