You need a firmware for your motor.
The Black Box doesn't flash firmware, only configs.
There ist a firmware that resolve most of the issues you are talking about.
I know, it is not easy to find an appropriate firmwarefile for Bafang motors, they are kind of cryptic.
If you flash the wrong file, you would brick the controller (but it's not a hard brick, only a soft brick).
You can revive the controller by flashing again the correct file. There are only a few files around.
In the attached archive there is the flashing tool an the bin file, together with the screenshot of the settings.
Be careful in choosing the chip type.
If it doesn't match by letter and numbers exactly as described, then this file ist not for you,
beside that, the flashing progress wouldn't start at all, so you cannot select the wrong chip type.
I'n of course NOT responsible for a bricked controller. It's only a suggestion,
it worked for my old BBSHD from 2018, and the same file worked with my actual bike from 2021.
They were two different hardware revisions, but for both of them thi firmware worked like a charme.
In conclusion, this file resolves the following issues:
1: The firmware works with the 52V battery (58,8V full charged). No error display.
2: The throttle now overrides PAS (and not viceversa). OK, it disables PAS while on throttle.
3: In the config tool you now can select 30 amps even on 52V battery, instead of 28 amps.
If you have an old laptop with Windows XP, use that, it's mor stable, but Windows 10 works as well.