What size are the carbon steel machine screws?
Rather than relying on EzOuts, you may want to look into using properly-sized
left-hand drill bits. They're available in
metric sizes too if necessary.
With judicious use of
Kroil (or some other available penetrant) ahead of time, you may find that a lefty bit itself provides enough torque during drilling that the screw loosens & backs out on its own.
Whatever penetrant you choose, leave it to soak in for at least twelve hours after application. Twenty-four is even better.
Be careful not to attempt using too
large a bit however as you'll thin the screw's wall thickness when drilling, making further extraction efforts difficult as the thinned wall tends to stretch from the torque on an EzOut-type extractor. Try to choose a bit roughly 50 - 60% the core diameter of the fastener to be removed.