NAN HA Gold - DD had no issues with it & was bf & ff at the start then we switched her to ff full time.
This is the exact same as us - NAN HA Gold, bf & ff, then went to ff full time, no constipation or any issues at all. Did try the S26 once, that stuff is PONG-EEEE! Smelt like off potatoes! Nan worked for us.

Best wishes for tomorrow! EXCITING!! xx