Basement toilet way too far from finished wall.
I had our house built 5 years ago roughed in for 1/2 bath in the basement. Now that I'm finishing the basement, I've run into a problem. All the walls are framed, drywall is up and bath is ready for toilet installation. Much to my chagrin, I realized now that the center of the soil stack is 20" from the finished wall, making the back of the toilet an unsightly 8" from the wall. I assume my options are limited. Either install an offset flange to get 2" closer, install a normal flange and deal with the gap using some shelving/cabinetry to disguise or rip up the concrete and extend the line 8"? Also, the stack is black ABS, can I safely use a PVC flange using the combination cement designed for both PVC/ABS. Also, what is the significance of Sch40/Sch80 and what is better to use in my situation? I tried to dry fit a flange for fit and it is extremely tight. Looks as thought the concrete floor which was butted up to the stack somehow contracted the pipe inwards to make it smaller diameter. Can I just rectify this with sanding if I decide to leave it where it is? Thanks