/opt particles 0
/opt obj 0
/opt hair 0
~~~
This idea is pretty useless. The default settings show the 3D items and flames, so changing defaults isn't needed.
If you want to see them at low graphic settings, just don't put the graphics at the minimum.
I mean, there's a reason why somebody changed his graphics to minimal, and this reason is low FPS. Objects and flames will decrease the FPS.
Sorry if my English is too bad to explain this well.