OS development question

[vfr400racer]

You can expect a lot of movement on all sides.

Mrfixit has done an amazing job at creating a well polished experience to accompany the Pinebook Pro from the factory. Ayufan has produced fantastic Ubuntu distribution as well. Those are meant to be solid out of the box experiences and use older kernels that work with the drivers from Rockchip. You will notice for example that the Mali GPU driver is more complete than it's open source counterpart - Panfrost. But we can't work on the Mali blob - only use it.

Both default Debian and Ubuntu are using 32bit userspace (programs are compiled against armhf) which allows them to use Widevine - it's the DRM to use Netflix, Amazon Prime and Spotify as examples. Widevine isn't available for 64bit userspace (aarch64) because Google.

I still haven't gotten around to play with Q4OS or ChromiumOS but I look forward to give them a shot.

Now on to the long term goal - full mainline and just loading the generic distribution image. There is activity on every front and the various threads from this forum can give you a taste.
For now, booting has a few wrinkles (you can't use something like GRUB) but at least several people are actively pursuing friendlier alternatives to the current uboot situation.
GPU side is very active for all Mali GPUs and I would advise you to keep an eye on Panfrost. Two years ago the driver was barely working, today is steadily moving towards es3 and you can enjoy fast desktop experience with gles2 and GL2. The developers are fantastic and we can see how Panfrost grows everyday.
VPU is still work in progress (watching accelerated video and so on) yet there is no problem with 1080p YouTube on mainline kernels.
There are a few wrinkles for resume from sleep and suspending(which work on default Debian) yet some developers are working on that as well. The battery life is good already and we have another improvement to look forwards to.
The audio is being pumped through the headphones and speakers at the same time for now. You can see several messages on the channels about possible solutions which are being considered. USB audio works normally btw

Overall - mainline development is very active and the end goal is to use it as a default. Until those remaining items are compete, less adventurous user or just people who want things to work as is, have stable and feature rich options with the customized distributions using the older base.

Hope the massive rambling is at least cohesive and it will help you a bit

Thanks for the insight. As I understand, there is a bunch of people, loosely coupled to  each other, trying to make things work for the PBP. But there is noone who puts these efforts together and tries to upstream this into mainline debian or the linux kernel. BTW, is it hard to get a specific customization or driver module into mainline linux?