SteeMan

Either use armbian-config to switch to nightly (unstable) builds, or build images yourself via the build framework.  But either way in doing so you would be switching from a stable build to unstable/under development builds.
Also at this moment do to significant changes in build framework introduced after the release of 23.02, no nightly builds are being produced as issues are being sorted out.

I'd recommend starting by submitting PRs for the board.  Build up some knowledge and experience with Armbian development and processes.  Then when you feel comfortable with the requirements expected of a maintainer, make that final commitment (https://docs.armbian.com/Board_Maintainers_Procedures_and_Guidelines/)

Buster was recently moved to end of support status in Armbian (Debian ends support in a couple of months too).  Buster was released nearly five years ago.  It is time to upgrade.

Armbian is basically the linux kernel and u-boot/install.  The entire userspace comes pretty much untouched from Debian/Ubuntu (depending on what variant you install).  So in general anything coming from upstream Debian/Ubuntu should work on Armbian.

From your log:
BUILD_REPOSITORY_URL=https://github.com/Mellow-3D/build
22.08.0-trunk
 
You are using a fork of Armbian that is a year behind current armbian code.  We can't help you in these forums as we support official armbian.  You need to contact the maintainer of the fork you used for any questions.
 

Upgrade to what newer version?  A userspace version (i.e. ubuntu focal to ubuntu jammy) or a kernel upgrade (i.e. 23.02 based armbian kernel to 23.05 armbian kernel)?
For userspace it is recommeded to do an install, as upgrades are not tested (but I just did a focal to jammy upgrade last night and they generally do work).
For the kernel, you can just do apt update/upgrades to continue following the builds over time (assuming you don't have your kernel frozen in armbian-config).

*minimal* is the key there, it really is minimal, you need to install armbianconfig if you want to use it: sudo apt install armbian-config
(Note: since you have installed 23.05, the apt repositories don't yet have the 23.05 packages available (some issues still being addressed) so the apt install may not currently work until that is resolved)

Are you looking at current code in github source? I think this has already been fixed.

That file is located in the armbian build system at:  packages/bsp/common/etc/X11/xorg.conf.d/01-armbian-defaults.conf
running a ./compile.sh will rebuild the deb's

Speeds lower than 1Ghz were removed in this patch to mainline kernel for stability reasons:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64/boot/dts/amlogic?h=v6.2&id=fd86d85401c2049f652293877c0f7e6e5afc3bbc

I'm not completely sure, but I think this is intentional, as 23.02 hasn't been officially released yet.  It is to be released this weekend.  The builds get pushed out to the mirrors which takes some time for all the mirrors to sync up as the first step.

I'll start with a basic question.  What are you trying to accomplish?  Looking at the link you provided, you are dealing with a device that Armbian does not support (and I doubt anyone around Armbian has any knowledge of this particular device).  You mention in your first post linux 6.0.  So I therefore assume you are looking to add support to linux 6.0 and Armbian for this device???  If that is the case, I would first ask do you have the skills and experience to undertake such a task?  Adding support for a new device into the mainstream kernel is a very difficult task, that often takes years of effort to get most of the features working (for someone experienced doing such tasks).
As for this particular respeaker 2.0 sbc, what are your plans for using it?  It would appear to be a specialized device for audio applications.  Which would lead me to believe that there are specific components on this sbc that will need proper driver support in the mainline kernel as well.  Which would likely make the task even more difficult to get these specialized features working on mainline.
As a general rule I would say that usually for a new device the process is to first become familiar with the manufacturer provided legacy linux code base (i.e. be able to build the legacy code from source and start building an understanding of what specialized components the sbc has that may need to be supported in mainline).  Then generally the next step would be to bring that legacy code base into the Armbian build framework to get it working there.  Then start working on getting basic functionality working on mainline (by basic I mean things like getting the board to boot  (building a mainline uboot and kernel that can boot the device)).  Once you get the device to boot on mainline, then you start working on getting each feature working, hdmi, networking, usb, etc.  Then finally getting any device specific features ported/working.
In looking at the respeaker 2.0 legacy source code download, it looks like the legacy code is linux 4.4 base.  There will be a significant effort necessary to bring a seven year old code base up to mainline.  All this is easier if you have the help of the manufacturer, but that rarely is the case.