TorBrowser 7.x Mac - Disable kMDItemWhereFroms extended attributes at least in Private Browsing Mode

In late 2016, Mozilla developers implemented kMDItemWhereFroms extended attribute metadata on macOS to behave more like Safari (however Safari, rather surprisingly for Apple, doesn't write xattrs in private browsing).

When files are downloaded, Firefox (v51+) writes the URL of downloaded files to a kMDItemWhereFroms entry in the file's extended attribute, even in Private Browsing mode. This metadata can be viewed using "xattr -l " and removed using "xattr -rc ", but on later versions of 10.12 this metadata is usually also written to ~Library/Preferences/com.apple.LaunchServices.QuarantineEventsV2

I plan to file a bug on bugzilla and ask the devs who implemented it whether they could add an about:config pref or disable the functionality in private browsing, but in case they don't respond, I thought I'd file a ticket here too since TorBrowser is now on v52ESR.

Here's the bugzilla bug where the developers originally implemented the kMDItemWhereFroms functionality.

https://bugzilla.mozilla.org/show_bug.cgi?id=337051

added component::applications/tor browser in Legacy / Trac owner::tbb-team in Legacy / Trac priority::medium in Legacy / Trac severity::normal in Legacy / Trac status::new in Legacy / Trac tbb-disk-leak in Legacy / Trac type::defect in Legacy / Trac labels

Here is the mozilla bugzilla bug I created. https://bugzilla.mozilla.org/show_bug.cgi?id=1374027

legacy/trac#22904 (moved) is a duplicate.

Trac:
Keywords: N/A deleted, tbb-disk-leak added
Cc: N/A to DrMikeTwiddle

mentioned in issue legacy/trac#22904 (moved)

moved from legacy/trac#22642 (moved)

added Bug label and removed 1 deleted label

added Disk Leak label and removed 1 deleted label

added Linkability label

added Icebox label

added MacOS Roadmap::Future labels

removed Icebox label

added Uplift Upstream labels

removed Linkability label

removed Uplift label

added Apps::Type::Bug label