If this has not been covered before..apologies. Have been known to use a yeast starter and use at high krausen and try to manually adjust the addition. Would be nice to have in the recipe calculator the yeast starter volume(eg 2 litres), SG (eg 1040), assumed SRM (eg 8), and IBU (=0) to enable a final pre starting ferment of the main wort. Just a thought. Cheers.