I have thought some on this subject but never implemented anything. Our traveling seems to get in the way of my pond management, but I am not complaining.
My suggestions.
Put shade in the cage.
Put a "feed tube" down into the cage where sinking (or pre-soaked) feed could settle down to a feeding plate under the shade. Give the RES a preferred environment to eat, a known place for them to return to eat. Then you could just drop feed into the feed tube (2" PVC drain pipe perhaps?) and it would go to the desired location without the wind or otherwise drifting off.
I'm pretty sure when I had RES in my forage pond they knew the feeding bell and at least some of them came to it. Because I could feed the FHM and GSH just before sunset and if I then threw a cast net would get numerous RES in the catch. Without the feeding I would get fewer RES.
I do not know if the RES were actually eating some of the food that made it to the bottom (the minnows could not swallow the pellets so some surely soaked up and sank before being fully consumed) or if they were just attracted to the feeding activity of the minnows (or perhaps feeding on the smaller minnows) but there appeared to be more RES attracted to the side of the pond I fed on at the time of the feeding.
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