Can Portal Settings be exported as part of Fixtures in my Custom App?

I created a custom app to hold all my customizations to documents, reports, etc. I thought by adding “Portal Settings” to [Property Setter] in my, I would be able to export whatever settings I made on Portal Settings (e.g. disabling routes).

{"dt":"Property Setter", "filters": [["doc_type", "in", ("Sales Order", "Sales Order Item", "Sales Invoice", "Sales Invoice Item", "Purchase Order", "Purchase Order Item","Purchase Invoice", "Purchase Invoice Item", "Naming Series", "Portal Settings")]

However, I noticed that following exporting fixtures, the resulting JSON file for Property Setter had nothing related to Portal Settings.
Am I missing something, or “Portal Settings” are not exportable?