I really doubt, that there could be a version of i.e. smoke, that looks like in those videos from earlier in this thread and has an equal effect to framerates like the stock one. In fact I beliefe, that it is in any case increasing the needed calculating power by a few times. Why that?
One of the still most FPS-killing things in visual effects is gradient transparency, even worse in combination with Antialiasing and even more worse with overlapping transparent objects. So now look at what we have in stock game: two crossing sprites of gradient transparency (animated too but thats to be taken out of thinking for now) - two pieces overlapping in the worst case.
Now what about those mod versions... many sprites of gradient transparency, allways facing the camera. Seen from side this may be ok, but as soon as you go behind a damaged plane and into a smoke trail, the number of overlapping pieces grows immediatly. Thats why I cannot beliefe, that it can be made equally to stock version, in case of FPS...
However, I am talking about weaker systems... on actual rigs, you probably won't notice the difference. But we can not be so superficial to ignore the 'poor guys'.
Lets say, your suggestion is worth of investigation, but probably not suitable.