So I’m assuming the sim will bring full functionality whether a phone is plugged into it or not? In this case couldn't you just tether it to your phone data? My phone has a wifi hotspot.So I have Verizon. I read online to that I had to get them to activate as a tablet sim card. Then I could use it. I explained to the guy behind the counter what I was trying to do. He had to go ask someone else and they managed to activate the sim card as a tablet before I installed it.
I have also read if you have a old tablet you could put the sim card in it and activate then put the sim card in the E10.
Hope that makes sense.