Yes/no. For the first use-case, yes. For the second, no. For the second use-case I definitely want to use the cell radio when the boron is away from home, but then turn off the cell and use mesh at home.
What makes the device OS on a boron be a stand-alone cell node vs a mesh node (without cellular)? Is that something that can be reconfigured dynamically?
I do not believe that the HA mesh network functionality would cover this type of use-case because I suspect that a mesh network needs to be unpartitioned and as soon as the boron leaves home, that would cause a partition (one being the home mesh connected by an argon and the other partition being the lone boron on cellular).
Sounds like my best bet would be to figure out how to make the boron ignore the cell modem so it can be a part of the home mesh and then work the cell modem explicitly using AT commands...