I could agree with this as long as it takes one of the manufactoring bays and takes (at least) the same time to break a module down as it takes to build one (for example if it takes 3 hrs to manufacture a module and you get 33% of the material when one is demolished, it should take about 1 hour (maybe a little more - 1Hour15Minutes) to recover that amount.
Sounds fair and since it is being carefully done, we should be able to retain most of the resources used to construct it.