It really depends on the threat.
IF you believe the allied team has a credible disguised covert ops-engy option, THEN I would not build the east gate. The reason for this is, if the CO-engy team accesses the fuel dump via the roof, the the only people the gate is keeping out are the defenders - BAD!
IF you believe the allied team CANNOT pull off any CO-engy option, THEN build the gate. It will take an engy to get thru the gate, you will get a warning, and have time to react. I’d rate this as unlikely
IF you think the most likely attack will be a conventional one with an CO-engy attacking the West gate with a satchel and then the fuel dump with the engy, then you are probably better off NOT building the gate since the extra time it takes to go around might give them just enough time to defend the plant.
IF you think the most likely attack will be a conventional one with an CO-engy attacking the East gate with a satchel and then the fuel dump with the engy, then you are probably better off building the gate. However, I’m not sure that there are a ton of benefits associated with this other than causing the attacking team a minor delay.
I guess in light of these 4 options, the low risk approach is to NOT build the east gate, UNLESS you don’t expect the Allied team to have any sort of credible CO assets