I use a Cyclone build as support build I mean yeah they have good durability but they are chunky and easy to hit. But I am quite effective at being support with it and tank when needed.
I just follow dog builds or hit and run style builds making sure they get out safely or get them flamer dogs off people.
That is why I call them support. You support allies that are taking fire. You drop them behind a sniper using a scope, scope blind. You ram their wheels off so they cannot run. You get the base capture point lead so they cannot run. You force them to come to enemy base to defend or your base to try to attack.
It does not always work.
You bring up a good point: it’s possible to turn any build into a support build by changing your playstyle.
Even when I’m playing melee/flamethrowers, it’s often the smarter choice to hang back and defend your teammates.
By that logic, MGs are the ultimate support build.
“You go in and fight them, ill rip off their guns and ensure you make it out alive.”
Kinda true though.
I like support builds, but sadly a lot of weapons that should not be support weapons these days fall into the support role rather than any other active attacking role. While the weapons that are really good at attacking are also very good at support as well, like for an example a cyclone or starfall, you can hang back and support with great success, you can rush the enemy with great success, you can brawl against enemies, you can snipe enemies, you can do practically everything and change your role on the fly, to the point that it does not matter if your cyclone build is fast or slow, a glass cannon or a hp brick, if it uses omnidirectional movement or not, it’s just good at everything in general, only countered by itself and weapons of equal omniuse capabilities
dps weaponry in general is the ultimate support, attack, weapon stripping, crowd control, 1v1, rush, camp, sniping, any gameplay weapon
I have a build that only has 7 barrier IX.
I use it to help my leviathan in cw and sometimes play it for fun in normal games. It’s often a disaster because teamates rarely understand how to play with it but sometimes a few allies play with the shields and the mop the floor with the enemy which is nice 
I play a support build more often than anything else. I have a few, but my favorite is on exhibit labeled as fuel getter (because it usually gets me fuel). It runs an incinerator and a Joko.
It is far more durable than it looks on paper.