From what I have been able to gather only maps apps so far. Definitely a bummer. If someone figures out a way to run non maps app full screen I would love to hear it. I only tried enabling developer options and messed with some of the resoulution settings but that did not help.
I finally got CoolWalk as well. As Millie indicated clicking on the maps icon toggles between full screen and partitioned. not sure how it works with Waze. Out of curiousity, are there waze app updates that might be pending to support the CoolWalk upgrade?
Android auto is slowly rolling out it's updated cool walk interface. I don't have it myself but have you tried clicking your maps app to see if it goes full screen?
It is an issue with the onboard modem if you turn on the truck and don't see the modem icon in the top right anymore. It looks like two arrows pointing up and down. Mine is intermittently down and I don't have any connected services including chare updates in the Ford pass app when it's not...