Tamper Free Dashboard

I am looking for the best vehicle (tablet, laptop, etc.) and software (browser set to LAN address, the new app) to place a more or less permanent dashboard "kiosk" on the wall.

I have tried several combinations - Firefox in full screen on a PC, the new Hubitat app on both iPad and Fire Tablet, - and all seem to leave a way for roaming pointers/fingers to get to something other than tiles. I have set my test dashboard to "lock down" mode but that seems to only protect the dashboard itself, not the options around it. For example, the little white bar at the bottom of the app.

Does anyone have a good way of locking down a preferably local dasahboard so that nothing is visible other than the tiles?

Fully Kiosk can be set that way.