Sure, thanks for working through all of the options!
If you make Verizon the backup connectivity, you could always run the Fire 8 tablet as a dashboard and run the 3.5G SIM as your primary connectivity.
If by chance you need Verizon for a particular race, then you can turn off the built-in telemetry, turn on app telemetry, and throw the hotspot in the car.
More about FreedomPop: https://www.autosportlabs.com/freedompo ... telemetry/
Verizon Data for Telemetry
Moderators: JeffC, rdoherty, stieg