Kudos to your shop for working on e-bikes at all. My experiences have been that bike shops/mechanics won't even do normal bike stuff, like working on brakes, when its an e-bike.
Removable battery is as good as a removable power cable right?
On the point about the power cable, this is more directed at hub Drive motors. If I can't disconnect your motor to remove your wheel, I'm not going to fix your flat tire.