unless you get both mods from the oade's...also the todd modd sbm-1 that i have somehow does not have the mic inputs disabled.
The mod itself does not require that the mic-pre side be disabled. Doug typically disables the mic-pre input side because the op amps he substitutes draw too much current, overloading the power supply of the SBM1. So he needs to save on power by removing the chips on the mic-pre side (with the assumption that most of us don't use the mic-pre anyway), reducing overall current draw. I don't know, but I guess he must do something to beef up the internal power supply when you get both mods.
The parts I use for the mod actually use less power than the stock parts, so I don't need to disable the mic input. So I leave the mic-pre side intact. On the few units I've modded, I generally leave the mic side alone. For the one unit I did for myself, I also changed out the op amps in the mic side, so that unit is mod'd for both mic input and line input.