Hey, grrrl -- no suggestion, but *much* empathy. When Bleuet was Dev's age, I was pretty sure you had to be Gumby in order to bf in *any* kind of sling or carrier.
I FINALLY (in desperation both times, naturally) learned to breastfeed Bleuet in the New Native (sitting up since he is such a "big" boy now) and in the Bjorn. Now I am planning on getting a new sling/carrier and am leaning towards some kind of Mei Tai, mostly because it seems like the best kind for bf'ing.
Oh, ETA that I never figured out how to nurse, or even just plain wear the baby in, the OTSBH. I hate that awkward unwieldy thing. I would get rid of it, but I hear that it can be good to have the padding once your kiddo is bigger.