Bought a new stem today (120mm, so 1cm longer) and pushed the seat up higher. Conveiently I cracked a new sprint best 5s power today. Nothing to do with it, but still. Saddle was probably a bit low looking at pictures again.

As far as the IAB position is concerned, when I did it (very briefly) during my ride today, I felt I could bring my elbows closer together and still remain stable. I'll try and a get a picture, but might be low on luck for that.