I’ve had tons of Flounder and Dab on everything from size 6 match hooks up to size 4/0 Manta hooks, (a lad on SSP on Saturday morning had a Dab hardly bigger than a 50p coin on a 2/0 hook!)
I never actually target Flounder but some of my regular marks are Flounder hotspots (Shields Beach, Market Docks, Jarrow Park) so when I fish those marks I prefer to use 2/0 aberdeens, (on a one-hook-flapper).
The 2/0’s always lip/mouth hook, so they’re much easier to remove – anything smaller usually gets swallowed, and can be a pain to get out (I know people have special methods to remove a gut hook, but I’d rather just have it lip hooked in the first place).
As for blingy Plaice rigs or fishy Turbot rigs – I wouldn’t know – never caught them, yet.