D'Addario Half Rounds are "Pure Nickel" ... If you shave the outer windings off of a nickel plated steel string you are going to have the nickel plating flaking off and eventually nickel splinters.
Half-Round strings are a lot more to be compared to than just dead sounding nickels. They have more mass. A .045 half round has the mass of a heavier gauge string so the overall tension and dynamic is different.
Nickel Plated Steel strings are never going to sound like "Pure Nickel" strings which most half-rounds are made out of. half-rounds are either, stainless steel, pure nickel, or nickel iron alloy. you will never find a nickel plated steel halfround...
The image below displays the difference between Round Wound, Pressure Wound and Half-Round. The Compression Wound and Slick Round are both Nickel Iron Alloy strings.
As your original question was cutoff by the title length restrictions I assume your question is:
"How long would I need to play a set of D'Addario XL Nickels before they started
sounding like half-rounds."
I would say they can't but they can sound like dead rounds.