I'm wondering which is the lower maintenance option. If I downshift at stops, lots more wear & tear on the shifter. If I don't downshift and start in a lower gear, lots more strain on the chain at those low speeds. Which is the better alternative? Mid-drive bike with a Bosch motor and Shimano 1X10 drivetrain.
If you don't shift down and start off in lower gears from a standstill your causing excess strain on the motor. Let alone the shifter. The cassette , the chain are what I considered wear and tear items. Mainly the chain and cassette.
The motor is not a wear and tear item like tires , brake pads , chain and cassette and even the shifter. Ideally like on a car you'd prefer the motor to last the entire life of the car , unlike like tires, brake pads , struts, clutch , etc.
Starting off from a standstill or stoplight in higher gears will cause excess strain on your motor causing it to possibly get too hot and overheat. So by not downshifting , yes you may reduce wear on your shifter , although IMO inconsequential at best the damage reduced, but your in turn causing excess strain on the mid-drive motor by not using lower gears from a stop or climbing hills.
A rear hub motor by contrast does not utilize the rear cassette for propulsion so the rider can start from a dead stop in 7th gear and the motor is not strained. Not that a rear hub is better or a mid-drive is better. They both serve the bike in two very different ways.
Like in a 5spd manual car you don't start from 5th gear at a stop sign/stop light. It bogs down the motor and transmission may stutter. While the mechanism in a car is different than a bike you still want to be continually in a manual mindset when driving a mid-drive powered ebike.
So you need to think to yourself, "Do I want to replace the motor first or the shifter first." If you want to replace the motor first then YES don't worry about down shifting.