Yes, porcelain tile. That’s a solution! Thank you. Instead of backerboard, could I do 1/4 inch plywood? Wouldn’t I get the same result? I still have to fix that raised lip anyhow, so if I still cut out that part of plywood that is raised, replace that piece, then lay 1/4 inch plywood over top, opposite direction, I can fix both problems, correct? (I feel like there was a tad too much space between plywood sheets, so laying opposite direction will solve that as well.) This was mine:
The transition isn’t a concern.
What do you think?