That's presently what I'm using, but I have added the mull version of the arkenfox user.js via Firefox devtools.

Fennec does release updates a bit slower than mull did via DivestOS's repo, unfortunately, and doesn't have a build up for these CVE's as of yet. Granted, I don't think FF android has these updates yet, but I feel like I remember Mull's updates making it to my device faster than FF's even, as they didn't need to go through external review processes.