Kerberos Propagation question

[Pax Industria]

Hi,

A colleague asked recently if   KDC's could replicate more frequently,  his
suggestion was every 3 minutes. That seemed as though it could have adverse
effects on the KDC's but i couldn't find anything in the  docs on a best
practice for how frequently / infrequently to replicate the database. I seem
to recall that propagation locks the DB, but I wasn't able to find a
reference to it. (I  could have made it up..., or maybe I just didn't see it
in the docs) Would pushing the database out that frequently be problematic?
Besides increased load on the system could that have adverse effect on
admin's working on the database?

Thanks for the help!