I think they didn't do that because they would need to have that system independent of the system inside the submarine or otherwise they would need to drill hol

I think they didn't do that because they would need to have that system independent of the system inside the submarine or otherwise they would need to drill holes in the main hull to provide power for that. Given the fact that the aystem was controlled by a cheap controller pretty sure they didn't spend that much money on the weight drop system either.