I think we should be careful to differentiate between 'impact drivers' and 'cordless screwdrivers'... My main cordless that I use all the time, has torque settings on it... so it's very possible to dial that down to do the initial run up of breaker screws. I don't use mine for that of course... I've got the Bosch cordless screwdriver that's permanently set a low torque for that purpose... with a proper torque screwdriver for the final tightness.
...just saying
...just saying