> The Adreno user mode driver (UMD) from Qualcomm Technologies is available as a downloadable Debian package and provides Vulkan 1.4 API support as well as the necessary GPU-related firmware.

Are they already using Turnip / Mesa as their Vulkan implementation or not yet? If not, they should. Valve are using Turnip on their Steam Frame.

That would be another step of working with upstream, besides the kernel driver.