Agreed, the one flip is a great way to mess up a steak. Multiple turns give the most even cooking.
Deciding doneness is a matter of predicting internal temp by the initial meat temp, time to cook and pan temp which I don't do well enough to trust. I just use a thermometer and pull the steak 5 degrees short of the desired temp and let it rest.
Or just sear the surface and put it on a rack(not a pan) to finish in the oven. And take the temp as above