I9300 Imei Writing Problem with BST

I had a I9300 with corrupt EFS yellow script on screen, Imei Null, unknon baseband, wrong serial number.

Repaired EFS with writing a default EFS with BST then Imei was 0049..
and yellow script from screen disappeared.
Flashed a stockrom Android 4.3 then baseband was ok.
Rooted the phone
When I try to write my original imei number into the phone with BST (instructions say checkmark Bypass Msl and Imei Patch) the baseband gets lost. The result is no connection with 523K Uart cable to write new imei.
Imei Patch destroys it.
Flashed stockrom and superroot again. Baseband ok again.
Wrote a SuperImei in the phone.
Phone works

What could I try now to get the originial Imei in my phone.
Or should i be satisfied with the working super Imei.

Thank you