I'm installing my roller plunger now, I see the problem you're referring to.
I went for option 3, which was to chuck the shaft of the new plunger in my dremel and sand down the mag release end until it was the same size as the old one.
Seems to work nicely -- haven't test fired yet.
I installed mine today, I had to use the factory plunger shaft as the lower part that is retained by the mag release plunger was 0.5mm in diameter thicker and mag release travel tightened right up but apart from that now with that, 13 pound hammer spring, flat trigger kit and over sized firing pin I'm sitting on 2 and a bit pounds trigger pressure...will test it on the range tomorrow.