I find development in Unity AR Foundation troublesome. It is annoying to build your app for each change and to make debug text appear onscreen instead of using debug.log.
Having a remote-controlled phone for AR Foundation would be one of the biggest additions to AR Foundation I can think of. It would speed up iterations a LOT.
As seen on the Asset Store (AR Foundation Remote | Utilities Tools | Unity Asset Store), it is definitely possible, but I doubt that man want to spend money on such an asset when they are beginning with AR Foundation.