dragging materials 1 by 1 is tedious,either all at one or a box that let us decide how much we need to move.
make the workers gain xp and eventually lvl up to increase success rate,with certain lvl limit of course, like say 3.
have to reselect stuff after each designate feed and inject is again tedious.
lastly,just a cosmetic suggestion, make the lab rat with different variety,I mean the cosmetic available,all just looks like golems with different accessories,make a rat face, a lizard face, or even fly facewould greatly enhance the minion making experience.
thats just my 2 cent, good luck on your next game :)