"smash the box flat" as opposed to "gently unwrap the box along its seams"?

Yeah, playing around some more with the planar map, the sides of my Tardis wall prop... which is similar to a plank, but with those circular, hexagonally arranged, indents in the front... the sides are not right with the planar... the edge pixels are just stretched or smeared down the sides.

Front and back work okay.

Closest result I get in Hexagon is with the cubic projection, scaling that to fit... but its not the same deal...