Most of the remaining severe crashes or rendering issues on Vulkan Impeller are specific to certain PowerVR GPUs. For example, we have flickering when rendering on the Google TV streamer, or a complete black screen on an Oppo-Something. Both are 9000 series (though I don't have a fully understanding of how the model numbers work yet).

For now we've disabled PowerVR. This issue tracks figuring out:

1. Are the sets or subsets of PowerVR GPU / Drivers that work OK?
2. Are there reasonable workarounds we can do to make them work?
3. Are there existing known issues we can use to bootstrap this discovery process.