Hi deaddog, and thanks for your feedback.
It appears you're not missing anything at all, as there did use to be more smoke, and a ring of fire, but :
1) with the new size and position options, it is tempting to create several fires at a time, which can cause a lot of lag : when updating the script, I was obsessed by this idea, so the aim was to find a balance between realism and gameplay. But yes indeed, I could (and probably will), darken that smoke again.
2) I really didn't like that ring of fire, seemed to me like an explosion of inflamed meatballs, so I simply deleted it, without trying to replace it. I still haven't found anything satisfactory.
Anyway, thanks again, I'll keep you posted.