I encountered this exact situation multiple times yesterday on a productive stream here in Iowa, 'Sny Magill'. I think it was mentioned early on that the fish did not feed as much in the depths; IDK about that exactly, but these deep pools do eventually shallow up: usually down stream, sometimes often with an outside bend tailing out into a boil line/riffle. If you have that boil line/riffle situation, I'd bet $ there will be some actively feeding trout in that slot, as the deep hole transitions/ shallows up. When I came to a deep hole like that, if my tandem soft hackle rig caught nothing at the deep front end of the pool, I wasted little time and worked the downstream side where it shallowed up into a boil line/riffles and 2/3 times I connected on fish with no change to my rig.
I guess that isn't really a solution to fishing the deep hole? More how this lazy old dude worked through it. LOL