custom parameters on postfix to avoid PMG overwrite

I asume main.cf.in is posfix main config file ( in /var/lib/pmg/templates) .. if I edit this file all saved actions on the gui will include this template changes right?
my idea is to change direct config, then postfix check and if its all right I will add changes on the template. does this make sense?
 
asume main.cf.in is posfix main config file ( in /var/lib/pmg/templates) .. if I edit this file all saved actions on the gui will include this template changes right?
no - as written in the docs - you need to copy that file to /etc/pmg/templates - and edit it there - the files in /var/lib/pmg/templates will be overwritten by a package upgrade.
 
yes - you need to manually create the folder