Using Emacs has taught me how important it is to have system configurations that can be code and stored in a readable format.
Even the settings in the customize option in Emacs are exported to Emacs Lisp and can even be made more readable when they are set using the :custom option in use-package.
It also makes version control easier as it makes it easier to take your changes with you whenever you set up a new installation and can see exactly how you configured stuff before.
Lisp is not what I have in mind as a configuration format for Lazarus settings, but YAML or may be some of the newer configuration formats might help in that respect.
Are the files created according to some known or set schema which can be translated to another format which can be translated back to XML in the form preferred by Lazarus?
Which leads to the interesting question. Are the settings dialogs automatically generated from the XML structure to the effect that additions of new configuration settings will result in the dialogs being adjusted to match them?