mleise i also had the habit of only one sided thruster on one module xD
^ i always used that module(before engine room&huge thruster is in vanilla)
and i had a habit of forgeting fe, if its even a habit
and even tho energy storage arent useless, its only useful in some rare cases, if dont counter the reactorless module, basically the only useful thing for it is to extend reach of the power supply(including the one u said).
about acutally using it as a storage, its acutally quite useless. since ur opponent can always do something like hit-and-run, and in the power consuming part, it really dont last long. and one big thing about it is that crew always take the storage's energy before reactor, which means reactor arent active 😉 (also it does cost two crews which arent such little 😃..)
(off topic) ur module seems to run out of power quite fast? since when your going foward and strafing/turning at the same time, there might be 4 huge thruster,one standard thruster and a engine room active at the same time.(or does it not matter for you xD)