From OpenSCADAWiki
Generally, it should be noted that any developments with the slightest hint, and the prospect of re-use should be standardized and maintained in the separate, own libraries and databases. It is not recommended to change the default configurations and elements of the standard libraries, and save your own, new libraries and elements in the databases of standard libraries. This will subsequently allow you to painlessly update the standard libraries, and to simply use the developments of your previous projects.