You're right, sorry :)

I wonder if it wouldn't be better to return `UnsureResponse.INSTANCE` if the value is null and the current topology id is different from the ClusteredGetCommand's topology id. If the value is non-null, it should mean that it's also up-to-date, so there's no need for an unsure response. If the originator got back only unsure responses, it would know to retry either on the read CH owners (if its topology also changed), or on the write CH owners (if its topology didn't change).