Mine also does, and always had, a noticeable shift from 1st-2nd, as compared to all other gear changes.
I am not a transmission expert, but I concur with your specialist. An Honda/Acura trained mechanic mentioned me these transmissions have some design particularities such as no band, which most other transmissions of the same generation do have. They just kick some shifting 1st to 2nd, and that is the way it is.My Transmission specialist took the car out for an afternoon, and basically came back and told me to live with it………………….