Question Change open_basedir and domain root directory in templates

[makeAlexandergreatagain]

I'd like to change the default values of open_basedir and the root directory for all new virtual hosts.
I know I need to copy the required templates from /usr/local/psa/admin/conf/templates/default/ to /usr/local/psa/admin/conf/templates/custom/ but I can't see those values in there.

How can I accomplish that?
(Disabling open_basedir would also be acceptable)