That is however, very disappointing, as I and others have been waiting for over 4 months for this to be added into the Unity SDK. In earlier posts it was mentioned that it will come in the March 2019 update.
So how long now do we have to wait before we can see and enjoy this new feature of instant preview?
And yes, I would gladly test it out for you when you have a pre-release (Beta).
Thanks for keeping us to moving forward to the better way.
We currently are investigating new method and try to enable the preview on HMD side, however there are lots of factors we need to handle carefully like performance and effect/impact when we also enable new features like single pass rendering, foveated rendering etc.
I'll update here our study result on the end of April, and definitely we're glad to share our beta version for your trial in advnace to make the functionality even better and robust.
Yes, we will enable this feature to let developer can simulator the change on HMD side on next release (Ver. 3.1) planning in July now.
However it might be a preliminary version to support Unity, since we expect it has change to hit errors on various PCs environments.
Please be noted for UE developer, we still need more time to migrate the mechanism from Unity. Will update the schedule after collect more developers trying results the new functionality on Unity version.