Worst case scenario is a slipping turn, where you may be varying your bank angle between 20-45 degrees to ensure proper alignment to final. You'll need to constantly adjust your pitch attitude to maintain the same airspeed.
Ok, we are referring to two different things. I am talking stabilized, you are considering a constant change. Stabilized at any given pitch/bank/power setting gives a certain airspeed. If you can judge and perform that same pitch/bank with outside ref you will always yield the same airspeed.
I also assumed power to be constant, should have said that.
Me personally, I stabilize with a power, pitch (bank too in the case of a slip), and configuration then verify safe airspeed. After that my ASI is secondary unless I make some other change.