I'm redoing my bathroom and installing a retrofit shower where the tub
was. I had a plumber remove the old plumbing and install and plumb the
base (cemented in) for me.

Problem is now one wall doesn't line up when I installed the cement
board. The 1/2" material fits 'behind' the shower base lip on one of 3
sides and the other 2 sides are ok.

I'm not going to ask the plumber to redo as it is cemented in. But it is
pushed to one side too much.

So, is there a trick I can use to make this look professional. The one
side that falls behind the shower lines up with the rest of the drywall
in the bathroom.

I purchased 1/4 inch cement backer board thinking I'd tack that on top
of the 1/2 so it'll line up with the shower pan and it does. But is
there a better way? The extra 1/4 will not, of course line up flush with
the drywall in the rest of the bathroom and it sticks out like a sore
thumb..
Thanks for any help..