They do have control, as even today when you get your unlock key from mimosa it unlocks it for part 15 (heck, the B11's can be used illegally if one was malicious and didn't want to file with FCC for the licensed hardware). If you send in the appropriate documentation, there is also a US Licensed key available as appropriate. If you try using other countries, the GPS will reset the radio in a few minutes. Mimosa definitely has the controls and software in place to support Part 97.
Mimosa does not need to get FCC part 97 certification, as HAM's are allowed to use non Typed hardware, so long as it meets the requirements of the application it is used for at the time. Therefore, We can use modified (in hardware or software) Part 15, and even licensed equipment (AM, etc) that then meets the intent of Part 97, or whatever part is appropriate for its application by the Ham.
So to me it seems like the simple thing to do is create a license key that allows the full band and TX power the hardware is capable of, and only issue those keys to individuals that have provided copies of their FCC Station License. It is then up to the HAM to ensure compliance with use and operation laws, just like every other piece of Ham gear.