Like most networks, anyone with direct physical access to the equipment has control of
the equipment. Most of it is not designed to be secure from physical access.
All hiding the SSID does is makes it harder for legitimate users to connect.
Someone who has physical access to your Jetpack has all of the access that they need. They can easily reset the password and any configuration settings that you configured to secure it by resetting the Jetpack with its reset button.
For that reason securing the display on the Jetpack does not gain you any benefits. The same goes with hiding your Jetpacks SSID, its not a real form of security. Instead you must focus on physically securing your Jetpack so that no one can see or access the device. Keep it hidden (but ventilated) from sight and don't physically share the device with anyone. Any guests you care to share with only need to know your WiFi password. There is no need for them to view the screen of the Jetpack itself.