In cellular products it’s more common to claim all devices to a single account than using individual customer accounts. If you already have a front-end that manages user logins and such, it’s typically easier to also just front-end the API calls on behalf of your customers.
The reason for the customer feature on Wi-Fi devices is that there already needs to be a mobile app to set up Wi-Fi in most cases. Using customer tokens allows a mobile app to securely communicate directly with the Particle API on behalf of the customer.
The customer feature does work for cellular devices, but generally adds unnecessary complexity.
And, in fact, as long as the Electron does not need to receive private events (including webhook responses), it doesn’t even need to be claimed to an account or customer. It only needs to be added to your product. The product device can still receive OTA updates, function calls, and variable requests securely even without claiming.