and wanted to test how much damage it does to green bitters....
it does a lot

just pressing space for 0.5 sec ( single ) press
and let the green biters just burn and run around ....
it does about 3000 / 4000 damage so I thought I grab my shotgun
and finish them off but when thay where still burning and the first shot
my game crashed... 2 times in a row.... ( shoting at burning green bitters upclose )
so i did a little bit if testing....
what i did, pull a few bitters, press as short as you can the spacebar to just let the biters burn....
so i got 5 orso green biters left so i threw a slow cap and shot a tiny bit more of the flamethrower
and then i tried to shoot them with my shotgun...
and the game crashed 3 more times on me....
thought you should know

Edit:
when the game crashes..
it " asked" to sent the save file and mods...
and some kind of factorio.current.log file...
so here is all you need
( shooting at burning after being slowed, behemoth biters with shotgun crashes the game )
Edit:
there are worms.... so i threw a few ( 5 ) poisn caps and when i ran in with the burning biters the game also chased...
and the game crashed 2 more times on me....
so that's total of 10 crashes in 15 min of playing