It comes down to what the certification basis is for the unit.
If it gets the required ticks in the boxes and is operated and maintained per OEM direction then you can use it for specified activities .. otherwise not.
However, considering that the reasonably expected life of a handheld is more likely going to be somewhat shorter and rougher than a TSO'd unit, why would the OEM bother putting a LOT more money into the design and certification efforts principally to reduce market penetration due to the resulting higher selling cost ?