i have something in mind... a floortile that heats up.
i know sounds odd.. BUT:
wouldn´t a hot flooring in front of a wall that inflicts fire damage be cool?
[damage in different highs the closer to the source/hotter it gets ye more damage is dealt (nuclear powered for endgame :3)"

pro: fire damage without using oil produkts
passive defense
more heat = more damage
"Bot save" AOE fire damage (they fly, hence no damage through the floortiles)
(no flamethrower animation but still burning biters..maybe even fps friendly)
...maybe more i guess

con:infrastructure must be upgradet to deal more damage
heat is lost over distance in the flooretiles kinda like heatpipes
floortiles are costly as the infrastructure
....there is this little possebility that this idea is a brainfart and only good in my eyes.

awesome mod anyway ^^ i love it
(very handy if steam is needed alot not only for power produktion...steamcracking etc.)

If u read the information tab and some post in discussion tab we are already working on that.
Anyway, thank u for your feedback and ideas but in any case, after finding a working implementation, I don't think we will move on create lethal damage weapon