Werner

Seems missing in kernel config. Feel free to send a PR and enable the module.

none of these are Armbian images. We do not support 3rd party OS.

I think the easiest would be to get/build an image with mesa-vpu extension enabled. Unfortunately there is no automated way to do the stuff this extension does while building, in a live system.
 
In general there are two ways to get hw acceleration: panthor or proprietary mali blobs. Former is from my feels better for general desktop usage and latter for hw encoding/decoding. Both cannot co-exist, no idea why.
Latter needs vendor kernel branch.
 
This would give you a Noble Gnome desktop image with Panthor driver enabled:
./compile.sh BOARD=youyeetoo-r1-v3 BRANCH=vendor BUILD_DESKTOP=yes BUILD_MINIMAL=no DESKTOP_APPGROUPS_SELECTED='browsers desktop_tools internet multimedia' DESKTOP_ENVIRONMENT=gnome DESKTOP_ENVIRONMENT_CONFIG_NAME=config_base ENABLE_EXTENSIONS=mesa-vpu KERNEL_CONFIGURE=no RELEASE=noble Feel free to test: https://testing.armbian.de/Armbian-unofficial_25.11.0-trunk_Youyeetoo-r1-v3_noble_vendor_6.1.115_gnome_desktop.img.xz

moved to csc
 
 
https://docs.armbian.com/User-Guide_FAQ/#why-no-universal-image
 
tl;dr: You are using the wrong image. Get/build one for your board

Yes. This is an example of a rk3588 based board of mine:
 
overlay_prefix=rockchip-rk3588 overlays=panthor-gpu opp-oc-24ghz The overlay names come from /boot/dtb/*/
find an overlay matching your soc and needs and enable by putting its name to overlays=. Then reboot. Having a serial console to read uboot logs can show if it has been loaded properly or in case it did not why.

moved since neither a review nor a tutorial.
 
I made a writeup just a few days ago how to get an idea about how Armbian puts its kernel and uboot sources together with an example for a different board: 
 

This device is community-maintained. Armbian core team does not monitor its status nor gets involved into development here. However anyone from the community can step up and send fixes.
 
I saw some stuff upstreamed from time to time for 5 ultra and max, hit somewhere between 6.16 and 6.18 I guess. When rockchip64 gets bumped further they will be available for these boards.
Since mainline is still under development though sticking with 6.1.y vendor kernel isn't a bad option since most things work here.
 
 
 

Tried this way? https://docs.armbian.com/User-Guide_Autoconfig/

https://docs.armbian.com/Process_Contribute/#adding-a-new-board

I don't think there are pre-built images with both ha and de by default. 
You can try to build your own by adding this extensions to your own userpatches and enable it: https://github.com/armbian/os/blob/main/userpatches/extensions/ha.sh
 
 

https://docs.armbian.com/User-Guide_Autoconfig/

This should have been addressed: https://github.com/armbian/linux-rockchip/pull/373
May take a while until an updated kernel is available via apt. You can always build a up-to-date package by yourself using the build framework.

Raspberry images are compatible from 3b up to 5b

Here are some:https://github.com/armbian/community/releases/

Maybe this helps? https://forum.armbian.com/topic/29427-shrink-backup-a-tool-for-backing-up-sbcs/

direct boot from nvme isn't possible. Boot loader (u-boot to say) must be present on SPI, eMMC or microSD.

Check here https://github.com/armbian/community/releases/tag/25.5.0-trunk.256
or on a mirror with archive https://docs.armbian.com/Mirrors/#current-mirrors
for what you are looking for. We're aware that some links are broken for yet to be determined reason.

There are for once some inconsistencies in terms of prefixes across various soc families and for the other configng isn't perfect (yet ).
Feel free to share your issue at its repository: https://github.com/armbian/configng/

fixed

Not sure if it is possible to use a local kernel source directory. At least I don't know how to do that. Easiest is probably just to create a repo and define url and branch in board your custom board config.

Yes, DB9 won't work.
But if, as eselarm mentions, a proper chip is on board already a simple usb-a to usb-c or c-to-c cable should do.
Check dmesg when connection to see what pops up.

Between days and month. Depending on time, issues, regressions,... 
Refrain from asking for ETA. Putting pressure on developers who give you something for free is abusive.

BOARD=uefi-x86

Install code { font-family: Consolas,"courier new"; color: crimson; background-color: rgba(0, 0, 0, 0.2); padding: 2px; font-size: 105%; } qemu-user-static package and retry