Your interpretation of my original comment seems extremely hypersensitive to me. Perhaps there is cultural difference at play here.
The experience I've had in hosting ten-thousand odd zones suggests that these resolvers do not exist. I've seen a great many claims but am yet to actually see a resolver that extends TTLs in the wild and so I consider them all but myth.
In the past there has been issues at the client - predominately with browsers, MTAs and stub-resolvers - so if I were to observe activity that suggested a stale cache I'd be more likely to attribute it to a bug (be it new or old) if no other data were available.
The experience I've had in hosting ten-thousand odd zones suggests that these resolvers do not exist. I've seen a great many claims but am yet to actually see a resolver that extends TTLs in the wild and so I consider them all but myth.
In the past there has been issues at the client - predominately with browsers, MTAs and stub-resolvers - so if I were to observe activity that suggested a stale cache I'd be more likely to attribute it to a bug (be it new or old) if no other data were available.