please can you let us know any timeline when the new version will getting release. (any tentative update)
New preliminary mainline 5.x kernel images should be available next week or before the end of April for RK3328/RK3399 for testing.
You have to remember that HDR(awaiting Intel patches) and 10-bit support is now wip and won't work as on 4.4.x kernel images.
HD Audio is also wip but will be developed further for mainline kernel.
H264, H265, interlaced support is also being redesigned so there will be new issues and improvements.
So 4.4.x kernel images are the most stable until support for all the components get merged into mainline kernel.