I'm sorry you feel my posts are useless, but the headers for the armbian version I'm running are not in that list. I used your build, linked to from your first post
$uname -a
Linux aml 5.5.0-rc6-aml-s9xxx.
$ apt search linux-image-current
Sorting... Done
Full Text Search... Done
linux-image-current-aml-s9xxx/now 20.02.0-rc1.038 arm64 [installed,local]
Linux kernel, version 5.5.0-rc6-aml-s9xxx
etc. (there is no other aml version available on a fully up to date system on which apt update has just run.
$ apt search linux-headers-current
Sorting... Done
Full Text Search... Done
linux-headers-current-imx6/bullseye 20.05.0-trunk.148 armhf
Linux kernel headers for 5.6.15-imx6 on armhf
linux-headers-current-meson/bullseye 20.05.0-trunk.148 armhf
Linux kernel headers for 5.6.15-meson on armhf
linux-headers-current-meson64/bullseye 20.05.0-trunk.148 arm64
Linux kernel headers for 5.6.15-meson64 on arm64
linux-headers-current-mvebu/bullseye 20.05.0-trunk.148 armhf
Linux kernel headers for 5.4.43-mvebu on armhf
linux-headers-current-mvebu64/bullseye 20.05.0-trunk.148 arm64
Linux kernel headers for 4.19.125-mvebu64 on arm64
linux-headers-current-odroidxu4/bullseye 20.05.0-trunk.148 armhf
Linux kernel headers for 5.4.41-odroidxu4 on armhf
linux-headers-current-rockchip/bullseye 20.05.0-trunk.148 armhf
Linux kernel headers for 5.4.43-rockchip on armhf
linux-headers-current-rockchip64/bullseye 20.05.0-trunk.148 arm64
Linux kernel headers for 5.4.43-rockchip64 on arm64
linux-headers-current-sunxi/bullseye 20.05.0-trunk.148 armhf
Linux kernel headers for 5.4.42-sunxi on armhf
linux-headers-current-sunxi64/bullseye 20.05.0-trunk.148 arm64
Linux kernel headers for 5.4.42-sunxi64 on arm64
So I have no upgrade path to a newer aml kernel with headers, and no headers package for the current aml kernel.
I'm sorry if this is wasting your time but I've only been running debian for 13 years so I may have missed something ;-)