I used 1/4" hardibacker board, and 1/4" firring strips (plywood I cut),
so the two pretty much matched up (this was for a tub, not pan, but same
issue). Then the tile of course set out from that, but not too bad with
the mortar (~1/16"+). Used a bullnose finish piece at the edges, and
looks great.

wrote:
I'm in the process of remodeling my bathroom. I tore out the
solid-surface and drywall that was under it. I'm putting in a
fiberglass shower pan insert. I'm thinking of using felt, backerboard
and then tiling over that.

My question is, the flange of the insert sticks out about 1/3 of an
inch. So, I'd have to use furing strips, correct? However, what about
the transition from the backerboard to the drywall (about 6' up)? The
backboard will be sticking out about 1/3" of an inch. How do I go about
this problem?

Thanks for any advice!