Hi Andi,
I think you’re mistaken. With both engines operating, you rotate normally at about 3 degrees/sec towards 15 degrees and wait for the SRS/FD to display and follow them. It should keep the speed somewhere between V2+10/20.
Maybe what you’re confusing is the engine failure at or just after v1 (the ones we practice a lot in the sim). In this case, apply appropriate rudder and smoothly rotate (2.5 deg/sec) TOWARDS 12.5 degrees. From experience, you usually aim just below that (maybe 11 or so) and let the SRS work out the ideal pitch to keep the speed not less than V2, then pitch to the FD. If you pitch straight to 12.5 degrees, sometimes it can lead to the speed reducing by a few knots initially which could cause you to go below V2 (especially if you pitch over 12.5 accidentally).
Champ