Thank you for your help Yuxin, I’ve updated to 4.1 and have indeed the option to disable it in the admin panel, but disabling it there gives the same result as previously disabling mwan3 through Luci.
It keeps pinging 8.8.4.4, changing the IP however works to stop it from pinging the google dns servers, so I’ve changed the IP for now and changed the track interval to 30min.
Disabling completely doesn’t seem to work though, then it reverts back to the default behavior of pinging every 5 seconds to 8.8.4.4