Excellent, that's the sorts of things I was hoping you'd find.
Myself, I'd gladly go for a bit more smoke from the stacks. Although what I'm really interested in is smoke from damage.
Heck, it'd even be great to have larger explosions for ammo ships, too
What kinds of settings are there? Is it the number of sprites, or size of sprites, or both? And their distribution?
If this works, I'm sure particle effects could be revised very nicely without affecting our FPS too much.