I think a fair compromise would be it only removes 100 toughness initially then ticks a couple points per second you stand in it, also doing HP damage through remaining toughness like fire barrels do… wait what? Fire barrels magically don’t do ANY toughness damage but flamers and bombers do; yeah, that kind of inconsistency is just arbitrary BS.
Anyways, that way it doesn’t punish you for daring to take high-toughness over HP. (which if fire didn’t exist would actually be good but it does and often you can’t avoid it grazing you on damnation due to flamer and bomber spam, eventually you will get hit which invalidates your choice of curios and that sucks)
I think that would be a fair compromise. If flat value is too “gameable” then 80-90% toughness seems fair. Or, you know, make toughness damage resist actually reduce the toughness damage the fire does. You know, make that stat not another giant lie. “Toughness damage reduction*” except bombers, and bursters. (snipers actually do not drain all your toughness, they just hit hard like maulers and crushers. If you have increased toughness from zealot/vet abilities you can take a sniper hit with zero HP damage… though toughness damage reduction doesn’t seem to effect it, have not paid close attention to that.)