I get the whole egg sinker concept and allowing line to run through it when the fish takes it, but its purpose isn’t to avoid the shiner from swimming up and away. They still use 2 split shot 6″ above the hook. I live in ND and am not familiar with Castle Rock Lake, so I was not aware if there was any current in it.
My concern was a lazy 16-18″ fish swimming up to it and just barely tripping the tip-up. While it is attempting to feed, a 1/4oz egg sinker plops in the silt and mud and causes a stir and spooks the fish. That’s where I’m coming from.
If you were about to eat a burger at a restaurant and right as you take the first bite something drops from the ceiling onto your table, is it going to surprise you? Or are you going to pause for a minute and possibly put the burger down?