Do ultralight reels benefit from carbon fiber drag washers too?

[philaroman]

Interesting...

If the clamping pressure is very low, I could see how compressible felt would  handle uneven pressure better than a hard material. So maybe it could be a better choice for very  light drag if everything is not exactly flat and parallel? And it would be more difficult to press everything nice and flat under very light clamping load.

Sort of a small window though.  Too much load for too long, and you will get the sort of problems that Keith noted.

not only that, but many(most?) Shimanos have a calibrated/incremental drag knob
a little spring-loaded post pops in/out of divots -- you can't set the drag "between clicks"
w/ bigger reels and/or higher settings, I actually love this feature for repeatability precision

HOWEVER, the oldest & smallest knob of that type has TOO FEW STOP-POITS/DIVOTS (10-12?)
[1000/2000-size of 90's models cheaper than Sustain & older than Stradic FH...  some later cheaper models, too]
at lightest settings, w/ non-compressible material (even, old crushed felt)
one click can be too drastic of an adjustment -- you can't have the EXACT drag you want
just have to choose between hair over & hair under & compensate w/ rod-handling
not a huge deal, but NOT ideal function either

old-style tiny boxy 500's don't use that knob (know nothing about sleek modern 500/750-size)
the drag sucks regardless of drag material (Rulon?), because it's a tiny 2-stack...  microscopic OD 
needs bigger metal discs, for which there's plenty of room in the drag well

[kevin cozens]

sure they will. a smooth drag is more important in a small light reel as you will be using very fine line right down to 1.5-2lb BS. The slightes judder could result in the line snapping