cache DNSBL query results on RAM Memory (for example; last 1000 IP) for more performance

Dear Sir,

Could you please implement mod_defensible internal cache on RAM Memory to store last e.g. 1000 IP's DNSBL query results, for more performance? (it may be configurable, and optional feature [0=for disabling])

making dnsBL query for each HTTP connection on webserver is not reasonable, and kills performance.
Unfortunately I can not use caching nameserver with udns library, too.
I really need caching feature inside mod_defensible.

BTW, it would be great if you add support for apache 1.3.x family, too.
there are many old servers running patched apache ver. 1.3.42

looking forward to hear from you,
may god bless you & help you.
Thanks a lot for the great project!