I know Flamers were suggested and the devs avoided it because it caused too much lag. I also remember someone somewhere talking about a post on reddit where a person writes up a way they could be implemented. Something about skeletons, hit boxes, and ribbons. Having trouble actually finding the post though. It'd be really helpful if anyone could find any quotes or even link the post.

Would probably make the flamer work like the meltagun works now but faster ailment application and the meltagun actually do direct damage rather than ailment.

I don't know. The description for meltaguns make them sound so much better than they are. Almost makes me miss the SM shotgun melta, ridiculous as that thing was.

Huh. Last I knew Flamers were still somewhat on the table, just not a part of the first wave.

I'm guessing they want to find a way to implement flamers that won't tank fps while looking good.
Heavy bolter belts had a similar problem once upon a time where a single devastator could cause the match to lag for everyone because of the wonky belt physics.

Why don't they just use the flamer mechanics from TF2?

The Ultramar Realm for a Flamer and the XVIIIth Legion! Or even better, a CombiFlamer so that I may remain effective at medium range as well!

It would have to have a ridiculously short overheat timer, otherwise 2 or 3 people would decimate an entire capture point room by holding the trigger down on the melee horde inside.

That's the point of using a Flamethrower on Choke Points.

I am no gamedesigner, but how about this?
The Flamer is just a cone, you stand inside, you are hit.
Flames are rendered on your screen, not on the server

Profit? Or impossible? as said, dunno

One thing is for sure, they HAVE to implement flamethrowers at some point, along with shotguns. Not having them in a 40k game is lame, they can be balanced in a right way.

Idea for flamethrower:

1. Simply take heavy weapon mechanics - short windup before firing (o.5 sec), slowing movement and strafing down to walking speed while firing, slower turn speed (hopefully would prevent op spray n pray running around rooms)
2. No damage dropoff, maximum 15m range (I know flamers have much longer range, but for balance purposes)
3. NOT a cone of fire, but rather a wider (1m ?) line of fire that can tag multiple enemies in that line (you still would have to aim for targets, and friendly fire wouldn't be that much of a problem)
   
4. After they fix ablaze buildup rate (I mean tone it down a bit), maximum ailment would do up to 300 damage DoT until you're extingished with penetration 100 (don't know if they have the mechanic fleshed out like this, I feel high toughness should reduce ablaze dmg). Max ailment would be applied only after 2 seconds of constant flaming the target (maybe down to 1,5 with some mod?). So to kill a vanilla character with 200hp and 100 armor it would take 2 seconds of tagging, holding an Ork in the flame for longer because of 250hp.

Also not a game designer so I have no clue how performance taxing it would be. Hope they find a nice flame effect like the one from Farcry series that can fill the screen without any performance reduction.

The baneshee scream is an effect that is applied in template cone.

Flamers would be no different other than the "application" of the cone stays around longer.