A few things to start so you know where I'm coming from.
I only pug STFs.
I believe everybody should have fun and fly what makes them happy.
I believe that current STF mechanics make high DPS the most significant contributor to the completion of optionals. In nearly every case, killing something faster is the answer. Sometimes you need to wait, or prep the target, so that multiple things can be killed in a short amount of time. In the end, however, you will still want to kill it as ruthlessly as possible.
I believe that when you enter an elite STF running something that you know could do more damage with some changes you are being inconsiderate towards other players. Even if you think it's a fun build, choosing your own fun over the success of the team is rude.
I believe that the idea of tanking is misguided, especially in STFs. Kill it faster and you won't need to tank, and you will be closer to completing the timed optional.
So, am I saying everybody should min/max to provide a bleeding edge of top 1% dps efficiency? Not at all. I do have one thing that I strongly suggest everyone incorporate into their build and a few benchmarks that I encourage people to see if they hit.
Today, in Season 6, the Tricobalt Mine is the single largest source of damage available. Season 6 also contains STF NPCs standing in the way of your optionals that are inflated gas bags of HP, some of which don't even shoot back. You will set your team up for success by finding room in your build for at least one Tric mine launcher and one dispersal pattern. Two launchers and one dispersal pattern will have cooldowns which coincide. This is a small addition any build can make, and one which can become the focus of a very nasty build should you decide to make it so.
One benchmark is the probes in KASE. One player should be able to destroy a wave of probes unaided. Check the how far they make it, then work on improving yourself until they only make it a couple of km. Some people will tell you to cc them. This is a stopgap measure and not necessary if you are properly throwing down the dps. The probes will keep spawning, so if you cc them away from the portal without destroying them all you will accomplish is delaying the inevitable.
Another benchmark is solo probe duty. This does not involve sitting at the portal. This involves killing probes as they spawn fast enough that red alert ends in time for you to full impulse to the other side.
Next, if you are a Tac/escort for sure, you should be able to kill the KASE cube that spawns after 2 generators have been destroyed. Once you can solo that cube, start working on cutting down the time.
You already know you can kill the probes quickly, you also know you can drop the cube in a hurry. Now you should volunteer to watch one side. In between probe duty you should pop one generator and prep another. Immediately after you kill a wave of probes pop the second generator and destroy the cube in time to catch the next wave.
If you can do these things there's a really good chance your pug will beat the optional.
Tric mines are considered balanced because they're destructible, take a long time to arm after deployment, have short range, and need to impact hull.
We need to make up for the 4 shortcomings so we can abuse the crap out of them.
Bare hull - When you see the red flash from the mines, you need to make sure not even a sliver of shield is up. Keep something in reserve, even if it's a torp spread, to hammer that last bit off.
Short range and arming time - Poop them right on top of cubes. In an escort you will carry the highest Dispersal Pattern, which is good. But you will have to rely on piloting against things like Negh'Vars. Cruisers and Sci ships will only have access to the lowest level, for the most part, but can use Warp Plasma and Grav Well to help with moving targets. MVAM gets high level dispersal pattern plus Grav Well, just saying.
Destructible - The Borg help us out here, they don't see the mines as a threat, which pleases my inner RP'er. Around gates and certain enemies you have to check their buff bars for FAW. The other real concern is the plasma torp from cubes. You need to pop this immediately to prevent the explosion from wiping your mines.
There is an additional mechanic working in our favor. If 4 mines deploy then they all share the same crit chance. If one crits, they all crit. We can finally pay the Borg back for their 1 shot torpedoes, and they can't even come to the forums to try to get us nerfed.
My MVAM is my most undergeared ship that I take into STFs regularly, and it's the most effective at erasing cubes. I don't really have good doffs for it and the shiniest thing I have is a Mk XI purple tric mine. Cubes blink out of existence.
Doffs, Grav Well doff, usually Evasive doffs, want an AP doff someday...
Negotiable: Consoles, balance Graviton Generators and shield cap, weapon type and TCD, as you like. Eng powers, do what you want. Toy consoles as you see fit. I have an Iso waiting to be unpacked on this guy, haven't gotten around to it. PH or HE, tractors or plasma fires.
APO or APB - APO against multiple tough moving targets (CSE) as you would need to apply the APB against all of them. APO will buff the mines directly. More importantly, as an escort you will need to drop the mine an appropriate distance from a moving target, then maneuver to drop the appropriate shield facing. For fatties that sit there, APB is fine, but I still personally prefer APO for the movement buff.
CRF or CSV - CSV. For multiple targets, derp. Now, for single targets we're basically talking cubes. With cubes, I have a single objective: to land 4 Tric mines on bare hull. The one thing that can really crap in my cereal is the plasma torp. CSV erases it the second it spawns. The range required for mine deployment means I don't have much time to deal with it. If I screw up trying to target it, I fail. If I stop shooting the cube to shoot the plasma torp then maybe a sliver of shield goes back up and the trics don't hit bare hull. So, CSV.
Doffs: 3 Technicians, 2 Evasive, or 1 Evasive 1 WP
Yes, I could get a higher level of DPB, but against anything with wheels it's going to look like a crop dusting with EWP, drop the mines, and turn to burn down a facing. The better dispersal pattern doesn't help if I can't get on target to bare the hull.
TBR is a touchy subject. Back to benchmarks, if you can herd a group of NPCs without spreading them out of CSV range, you are doing it right. Also, stationary targets eat every pulse, so buff it and deliver it. And it will crush plasma torps.
Consoles are negotiable, Aceton Assimilator will pop plasma mines once it starts pulsing.
I will try post my Kar'fi later, which is really the last word in abusing game balance to erase NPCs.