Most addon developers are now using the preferred method as outlined in the Learning Center > Addons, using xml files to hook the addon into P3D. This is a much better method than the old way of using scenery.cfg.
Many are using the free Lorby Addon Organizer (https://lorby-si.weebly.com/downloads.html
), which in a way is the replacement for the old configuration editor, where I and others prefer creating our own xml strategies.
Do you have a specific problem or was this a general question?