Never use silly high emission values for camera visible lights as they cause gross aliasing artifacts. Split the signal; low strength for camera (and sharp reflections?), high or as required for the rest. Emission material should also have a material ID which can be used in comp to drive the glare node. And, if you have emissive screens, you might want to turn off multi importance sampling for those; the light emitted from those will be more grainy, but it doesn’t matter since their effect drowns out from the main lighting which is now less grainy. I typically turn off MIS for everything that doesn’t contribute/bounce lighting around in a major fashion (might be overkill). If the overheads are significantly dimmed down, then I wouldn’t touch the MIS for emissive screens as they provide a major contribution to the lighting of the room.
Edit: Sometimes I go probably beyond stupid in my hunt for cleaner and faster.
Mesh light - camera visible only (can be easily textured or put behind a thin grid).
Area light - glossy visible only (since they clean up faster). And you can assign easy/manufacturer values to them (important for relativistic lighting in some cases).
Huge area light - diffuse only (renders very clean).
Huge area bounce lights - diffuse only (needs to be colored according to what they simulate being bounced from).
If you have grand differences is light areas, you might want to split it up in two renders; two 100 sample ones added together (or 50 big/150 small) looks far better than a 1000 sample single render.
If you need a thick visible grid (typically metallic) in front of light, the mesh light will need to be glossy visible as well (and drop the area light). You will get more noise though but can’t be avoided I think. Example of what I mean (grid is a 3d metal object):
If you can live with faking the grid (just a texture/node based), somewhere around here recently posted a way to “directionalize” area lights - hugely useful. Example of what I mean (grid is just a texture masking the light on a single plane):
(can’t show full pictures).