I would check the switch first just to see what kind of shape it's in.
I am totally satisfied with the repeatability I get with X on mine. Maybe .001" or very close to that. It has stayed that way since I first started production runs a few months ago. I haven't reset anything and all my parts are still sized within that tolerance.
Honestly .005" would be good enough for our parts. Now for someone like John Grimsmo that machines very tiny titanium parts, I can certainly see the need for much better accuracy.
Just because I get acceptable accuracy now does not mean that if you guys find a good replacement switch, that I won't swap it out. I will be watching.