Thank you, I see this is simply a matter of a difference in experience, and like all things with this game, coordination between teammates becomes important. (So while a buff engineer might be good, it's also good to have a more standard geared engineer on hand in such cases)
The buff tool is actually one of the driving forces behind the "gunners are really not very good except for select guns and only because you need to change the range of engagement" arguments.
Basically an engie with a buff hammer is more effective, at BOTH repairing AND shooting, than a gunner, in a wide variety of situations.
It is very good.
Also to give you a breakdown and some tips on the buffkit:
1. Guns only buff for a short duration - 20 seconds. You'll want to prebuff them (buff until last tick) and only complete the buff when you're about to shoot.
2. Turning engines (main engine if you want too) are generally what captains will want buffed. Buffing turning engines is amazing - basically makes you have permanent phoenix claw. Also engines only take 4 hits to buff, making it extremely quick and effective. NOTE: If you buff one turning engine, make sure you buff the other! Just like having lopsided damaged engines, if only one is buffed it makes the ship veer off and very difficult to steer.
3. Balloon buff is also extremely important, and it gives your captain much better vertical mobility. Seeing a pattern here? Mobility is key to high level engagements - everything you can do to help your captain get your guns into arc and stay in arc is critical.
4. All "hull components" aka everything except guns, buff for a long duration, like 2 minutes I think. You'll want to both buff, AND prebuff engines and balloon. This way, during combat, if you see them about to fall off, just hit them once more to carry you through the battle. During downtime your job is to rebuff/prebuff everything once more.
5. Counterintuitively, hull buff is the least important. It generally will not make enough of a difference when you're being focused, and the hull buff takes an extremely high number of hits (like 15 or something).