I'm sure you know that Acumatica customization project is just a big XML file that has some links on external files. You can easily export ZIP archive with all linked files and store it on the file system. Unfortunately is not really good for tracking changes.
But do you know that Acumatica has very easy-to-use integration with source control where you can export project as set of text files? Let me show you how to use it:
As I said customization project is big zip file, but it can be split by items, that you can see using File -Edit Project Items menu:
To export them click on Source Control -> Save To Folder
Good thing that you can upload it back the same way - just use Source Control -> Open project from Folder menu.