I am not too sure about the CFM engines but in our IAE engines FADEC is monitoring till 50% and after that it is passively monitoring the engines. You can find the information in 1.70.80 page 4. Of course it does not explains why FADEC monitors it only till 50% N2 and leaves it on to us human beings after that!!!!
Also it is not written anywhere but a very wise MEA captain once told me to start the second engine only after the first one (#2 in our case) has reached peak EGT and there is a drop in the EGT. This way at least you are sure that you will not need bleed source in case of engine tail pipe fire or hot start.