If the company is billing for your travel time, then the tech should be paid. If someone takes their work van home & is expected at the customers location at starting time, then the tech should get paid from the time he leaves his home- as the customer is paying travel time for that tech to be there. It doesn't matter where he came from ( his home or the shop). The same is true at the end of the day. It doesn't matter where you're going, if the company is billing for your time, then the tech should be paid.

If the company didn't want to pay me to travel to & from customers at the beginning & end of the day, I'd leave their work van at the shop & drive to & from work on my own time, using my own gas, in the comfort of my own car. It's a convience to the company & their customers if I take the work van home- it's not a convience to me. Who really wants to be responsible for the work van at their home- I don't. If the company wants that convience they should pay.