Arvo

Why not buy an Armbian supported SBC? Most TV-Boxes are crap. Overheating and low-quality. For better quality you also pay a lot more. So then why not buy a good SBC?

RK3399 ain't that expensive and has great IO. RK3588 is high end so cost more, but it's future proof.
OrangePi5+ should be best value. I don't have it, so can't say much about it. 
NanoPi R6S/R6C isn't that expensive. The C has NVMe and USB3, and very fast CPU.
 
If you want to use full sized HDD's then look at the Odroid HC4. It has the S905X3. As powerful as RPi4(when not OC) and 2 SATA for full sized HDDs. But no USB3 or other IO. It does have HDMI.
 
RK3568 is also a SoC that has great IO and not too expensive. Not sure if there are Armbian supported boards with it.
RK3566 less IO but still better than any RPi.

I only had one ok TV-Box from a bunch. The Mecool KM6 with S905X4, but that doesn't have Armbian support. S905X3 should have better support. But you are never certain all hardware will work.
TV-box manufactures ofter use different components for the same model TV box. So some people might have wifi working, but others don't.

Got an answer from SinoVoip - "Our DC port size is 4.0X1.7".
Will leave it here - just in case, if someone is looking for BPI-M2 Pro power plug specs.

New packages uploaded to the repos (it may take some hours to synchronize).
Bug fixes: X Desktop no longer restarted on package install, so it can be installed from a desktop session (NOTE: Since the old package is still going to restart X when uninstalled, it is recommended to do this update from console). MPV now is not failing when it cannot create EGL surface (it will just default to standard x11). CEC is now working on several boards (tested in RockPro64 and Rockpi 4B). New features: MPV is now RKMPP accelerated, and allows 4K YouTube Playback (see instructions here).

Ok, it needs one more change to fix the boot issue (besides working bluetooth).
Right now the service type is set to forking but the brcm_patchram_plus_rk3399 binary is not forking so systemd treats it as not successfully activated / activating.
 
Change Type to exec and it should be properly treated by systemd.
I adjusted it in the PR too: https://github.com/armbian/build/pull/2480/commits/92729573cea1aa786432e1dce42d641019e8bcd4