Managing my crew on EV charger installs without killing my margins

Got a 3-man crew handling all these 240V EV charger jobs, but the downtime between installs is killing me. Just paid $85 an hour per guy for a full day on a Qmerit hookup that took half the time, and the customer's nickel-and-diming over the conduit run. Switched to Klein Tools clamp meters to speed things up, but I need a better way to schedule these without eating into my 20% overhead.