Okay, I misunderstood it. Yes, what you're suggesting (basically to only keep the glue for the current query and not to cache it, right?) would be a fix. Buuuu

Okay, I misunderstood it. Yes, what you're suggesting (basically to only keep the glue for the current query and not to cache it, right?) would be a fix. Buuuut you'd have to consider that legitimate glue usage includes A records for NS records.