Could not repair hardwares on a Big Sur beta Mac w/ T2 Chip

It would be really (awfully) surprising that a screen cannot be repaired by an authorised dealer because T2 chip does not allow.

Would be really interesting to read from Apple T2 chip specialist what's going on.

You can restore the T2: https ://mrmacintosh.com/how-to-restore-bridgeos-on-a-t2-mac-how-to-put-a-mac-into-dfu-mode/

Oct 11 Update
Have tried restoring the T2 firmware through Apple Configurator 2 + DFU mode on my Mac.
https://support.apple.com/en-gb/guide/apple-configurator-2/apdebea5be51/mac 
AND mrmacintosh.com/how-to-restore-bridgeos-on-a-t2-mac-how-to-put-a-mac-into-dfu-mode/

Notice you have to restore your T2 firmware instead of reviving it. The restoring process will also erase your internal flash storage so proceed with caution.
After these steps, the Mac, including the macOS, RecoveryOS, and any other partitions, is completely erased. Meaning you will need the online recovery (https://support.apple.com/en-gb/HT204904) to get your OS back. I didn't try internet recovery when I was at home, and I took my Mac directly to the Genius Bar.

It now passed the AST MRI test (which means, theoretically, my Mac is repairable). However, they still cannot fix my Mac because they are concerned that if my Mac has no bootable system, reconfiguring the T2 chip might lead to "further hardware and software issues." At the Genius Bar a specialist tried internet recovery, but the system will shut down itself when it finished downloading the RecoveryOS. The specialist informed me that this could be a verification issue when my Mac is trying to download a later version of MacOS which is not yet distributed by Apple.

In the end they told me to wait until Apple release Big Sur customer version. I'm more than disappointed in their solution but I could do nothing...

The Genius Bar clearly needs better Geniuses… you can download the macOS Catalina installer from another Mac, make a usb drive installer, and install it.

It's amusing that the Geniuses neither know of to restore a T2 and neither know how to install macOS.

Just reinstalling macOS 10.15 WILL NOT solve the issue. Reinstalling 10.15 will not downgrade the T2 firmware so the Genius Bar still won't be able to reconfigure T2 when repairing.

@ Nivek_J So, what is the correct answer. The one you marked as correct doesn't work ?

@Claude31 
Yes. I mistakenly marked one of the answers and could not revoke that green label.

I'm contacting Apple Dev Support for an actual solution. They are yet to respond.