I broke down and spent the money on a Hop Stopper (all SS version). I've only used it for two brews, but it's worked very, very well. No issues at all with my 30-plate chiller.
I've often wondered about this - been on the edge of getting one a few times... whats the most amount of hops you've boiled with it?
My last batch only had an ounce of pellet hops, but it had 27oz of whole leaf hops.
(It was my harvest IIPA).
Though I did a 5 gallon pale ale the first time I used it that had 6oz of Cascade pellets and had no issues whatsoever. Nothing came through the screen that I noticed and I was watching the hose out of the kettle like a hawk since it was the first time I was using my plate chiller as well and was a wee bit paranoid about plugging it up.