Rings atolls exist because the volcanic mountains they form around have sunk into the crust and dropped below the water line. Drip and plume volcanism should generally result in longer dwell time for volcanic islands, the thicker crust doesn't deform as rapidly so the islands sink far less after they stop erupting. Thus you're not likely to see ring atolls, the sea mounts never completely retreat and the reef defends it from eroding flat. Coupled with the global range of corals you will have large offshore reefs around every coastline that has been above water for any length of time.
Ash
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