Here is my 2 cents on the matter.

Is this an exploit? No
Is it in poor taste to do it this way? I believe yes, seems like a cop out to me but that is just my personal opinion.
Should do the Devs do something about it? I think they should, the entire premise of the fight is you have 12minutes to remove as many mechanics as you can and then defeat the last boss, by circumventing that i feel like you are just cheesing the point of that turn.