You can add a damper mount to the driver side. Cheap ones on ebay are about 45.00 up to about 150.00 for name brand. I put a Weapon damper on recently due to a couple of broken driver mounts in recent weeks. I also reinstalled the front bottom to frame rail mount. Between these, I can feel a better transfer of power to the ground and idle is smoother.
Best way to look at it is your engine spins the flywheel, sending torque to the axles, to the wheels, to the ground. If part of that torque is intercepted before the axles and is used to move the motor, which is what happens when mounts are broken, that is energy lost to the wheels.
I'm no engineer, but physics would seem to dictate once a motor on broken mounts reaches the end of its flex journey, full power is available, but you would go through the same process of initial loss on each shift. In other words, it isn't likely a loss you would see on a dyno, but would in the 1/4 mile.
Wheel hop is another consequence with broken mounts, as well as vibration, etc.