I have not seen many Blues caught above Idols, but I have seen a few, less that 6 I would guess.
I would target cats below Idols, not above.
Fish for the Flatheads with livebait, Channels and Blues with cutbait and chicken liver. Use "J" hooks for the liver, circles for the other baits. Fishing for cats below Idols is not a dainty affair, use decent size line and equipment. Use heavy wire hooks, not the light wire stuff. Don't be surprised if something with stripes shows up......below Idols.
Good luck, there are some big strong fish there in the Spring.....