Knott's cut-out test is pretty simple. You want to sit on a hard, flat surface like a straight chair or the top of a retaining wall with your sitbones firmly on the surface, and your legs and torso more or less at the angles they'd be when you ride. If your soft parts feel smashed against the surface, you'll probably want a saddle with a cutout. If they feel spacious, you might do better without one.



.... but, if you're feeling a need for a longer channel on your Bontrager, then it doesn't seem likely that you'll want a saddle that has no room for your soft parts (whether it makes that room with a cut-out or with a channel).