Keyboard layout customization

Hi everybody, I'm new on this forum and also a new Kali user.

I've got the following problem:
When I create an ISO build (Kali 2018.02) and I want to customize some parameters like language or keyboard-layout/variant, I use the "lb config --bootapend-live" command. The auto/config script works well and I can check that the config file is correctly modify with my new parameters but, when I run the "build.sh" script, my parameters don't be upgrade on the build :(.

I've also seen that the first lines of the running script do a "lb clean" command and reset the config file with default value...

Am I doing something wrong with the lb config command or is there any other issues to solve my problem (maybe to build an ISO without the script) ?

Many thanks for your answers.
Cobra