zebra tc75x -> disable roaming
Are you able to disable it manually in the device settings? If so maybe you could use the watchsettings to capture the setting value and then writesecuresettings script in order to set the value. I haven't had much success with writesecuresettings under AEDO just yet but you should be okay given that you're using Android+ still.
There also is the Zebra MX path that I'm surprised you didnt check: