Save a Project with "Model in one file" Persistent Propriety mode

Hi, i have a project in ODM saved with the Model Persistent property set to "Model in multi file". I think to have understand that when i set the Model Persistent to the value “Model in one file” ODM don’t create only a single file for all the structure/model include Logical Relation a Phisical Model (i hope to see a single xml file) but howhere it save the model with some subdirectories like "businessinfo" "datatypes" "files" "logical" etc etc and inside thisyou can find 4 files, one with xml extension and 3 with ".local" extension, it’s right?

so if i want save an unique file for all my project i need to make a zip or there is a possible to convert it in a single file?