That makes sense actually. With the toe of the boot hanging over a bit, it is logical that you would be able to pressure your toeside edge more effectively. You also mentioned increasing your forward lean if I read that correctly. This may also have had a major impact as increasing forward lean will cause your lower leg to be at a much better angle to force you to flex your ankles more and keep more weight over the top of the board. Either way, it sounds like a positive change.
Generally speaking, we try to keep the binding centered on the board but so long as you are not catching your toes on the snow when in a toeside turn with high edge angle, it is not hurting anything. I am curious though about your new bindings versus the old ones. Do the new ones have the toe ramp (often called "gas pedal") when you old ones did not? If so, this could be the reason for the improvement too.
Glad for the improvement and like I said, if your toes aren't dragging in the snow, don`t change it for now.
No, they do not have a toe ramp. They are last year's Roxy Rock It Power rear entry bindings. I picked them because they are two straps and the strap over your foot actually pops up when you pull the highback down to get your foot out. I tried Flow NXT's last year and had a hell of a time getting my boots out of them when I had them tighted the way I needed them. The forward lean would not go forward enough for me so I sold those. I am tired of strapping in and wanted to try the rear entry again and with the pop open action of the strap I can get my foot out sooooo much easier. This year's Roxy had canted footbeds and harmellow on the bottom, so who knows I may try those next year. For now, I am liking these except I can't move the bindings back any further unless I change my stance if I rotate the circle plates - and I don't want to do that at this time. Did great today on the black, however, after all day yesterday my right knee is screaming at me so we had to come back so I could ice it. Still wondering why my back knee is giving me problems when snowboarding and wondering if I may have to change my stance or binding angle - now with my toes over a little making it easier to do toeside, makes me wonder if I should try difference stance widths and a different angle on my back foot. If I could just get this all figured out it and alleviate the back knee pain it would be WONDERFUL!!! lol