Im running a pretty crappy system by todays standards, and I accept that, but since cata I haven't been able to do 25 mans without serious lag, and with the LFR tool im having trouble running as a healer because of it. Basically I want to turn off the boss effects during fights as I think I'd be alright without them, except i dont want to turn them all off..
Example of what id like to turn off is the Resonating Crystal effect on Morchok when you have the beam on you the screen tints red and in 25 mans as soon as that happens for the first time in the fight I drop to 0 fps and lag out for about 20 seconds.. But at the same time I dont want to turn off the ground effects and other effects like the black slime on the ground for his other mechanic.
Unless you count spell effects (all spell effects) etc to low then no, there is not specifically to boss spells.
You just have to hope blizzard will patch more stable code to bosses that cause trouble to some computers right now.
darn.. i was hoping their was a separate command for different types of effects.. like the death fog. It'd be nice to loose the screen tinting effects and yet be able to see healing circles in full effect.