Thank you also @fredldotme. That sounds great. I'm very eager.

@fredldotme I have the result of the command. I sent you an e-mail.

Ok, I have the device and can try that command. I think first I have to install UT on it, right?

Today I've got a F5122 and I would love to see it with UT. But I think I don't have the capability to make it happen.

On https://github.com/Halium/projectmanagement/issues/98 you can find:

xsetiadi asked on 21 Aug
does this will work too for xperia x dual? F5122? @fredldotme

fredldotme commented on 21 Aug
In theory yes, practically I don't have the device available. But since I modified the source in a way that's not specific to F5121 it should work just fine.
The only area I could see issues with is ofono needing an override to support the second SIM tray.

On XDA I found this thread: https://forum.xda-developers.com/crossdevice-dev/sony/universal-sony-dualsim-patcher-t3930983 Perhaps a solution for the dual sim issue?

Yes, you can see it.

I have another problem with start of Teleports. I got the code via SMS but I cannot fill it in. Refused with: Falsche Authentifizierungscodelänge. Device Moto G2 titan.

With flashing the new image of today the device works again. All dates are lost.