When I was in the tng dept on the 737-300/400, we would try to find ways to amuse ourselves. Yes, it was a sim but the fidelity was good. Anyway, we flew an entire check single engine. Taxied out, took off, did the stall series, all the approaches and go-arounds single engine. Not a big deal. Just trim, trim, trim.

On takeoff, you just had to add thrust slower so you had enough rudder authority but even with a med fuel load, it wasn't a super challenge.

Now, on the line? No way one could 'accidentally' takeoff single engine.