That is a loaded question. Stance angles vary so much depending on too many factors to just say do this. My personal setup on my split is 38f/30r front foot flat and rear foot has cant/lift. On other boards I ride as little as 5 degrees split or 15 degrees different, depending on what and where I’m riding. A few guys here ride duck with A/T boots. I personally don’t see how, but that shows how we all differ at a biomechanical level. I would start with a setup close to your softie setup, and carpet surf. Make a change at a time until you get rid of any hotspots in your boots. A bit of overhang is fine for now, less than a half inch at most. Go play, and repeat as needed.

On the split board I am riding about +25f / +18r in modified Scarpa F1s. Like barrows, I made some changes that increased the forward flex. At this point my F1s have a forward flex much closer to a softboot than most hardboots. Lateral flex (side to side) is also important for the softboot “feel.” The Voile Mtn Plates I am currently using have a lot of lateral play which helps my weight shifts forward and backward on the board. I don’t really trust the Voiles strength-wise though and I am very anxiously awaiting the new Spark plate bindings with built in flex for next year.

I ride softboots inbounds at angles of about +21f / +12r and alpine hardboots on the groomer days at about +48f / +45r. I have only slightly increased my angles for the AT boots on the split. I have never ridden duck or 0 degrees so I cannot say how the AT boots would perform at those angles. I assume lateral flex would become much more important for shifting your weight forward and back along the long axis of the board.

For carving on groomers, I ride a stiffer boot than on the split. I do know several riders (I think Jon Dahl is one) that ride the same hardboot for carving, splitboard, and resort powder riding. That would be convenient, but doesn’t work for me.

For any inbounds riding I need my toes and heels at the edge of the board. Any overhang and I will boot out when I hit a groomer and start carving. That is true even on my powder board if I am on a groomer heading back to the lift. On the split I find I rarely lay down a trench for a variety of reasons. The vast majority of my turns in the backcountry are skidded on some level and I am able to ride with a bit of overhang (not a lot though).

For bindings, the Bombers might work for both purposes, though I would contact them to make sure. If it does work and you are planning to eventually mod them to fit on the slider plates you might consider buying a pair of used TD2s instead of the new TD3s. They will still be fairly expensive ($200), but they really are bomb proof. You can check the Bomberonline.com classifieds or put up a WTB on the site. As I mentioned, I am really excited to try the new Spark R&D hardboot split bindings with the built in lateral flex.

Good luck!