Asking for opinions on straightening shower drain pipe

[wwhitney]

Most of the P1056-22 will be surrounded by a 4" coupling of which probably an inch of the bottom will be buried in gravel and the top portion exposed to nothing because the 4" coupling will be holding back the cement.

Nice idea for a block out on the concrete. I assume a 3" coupling is too small to fit around the P1056-22? Any concern that the 4.5" hole in the concrete is too much as far as supporting the Kerdi-drain? I guess you could infill the coupling block out with small pebbles.

Cheers, Wayne