Just a heads up.
Thanks to Stefan's excellent recommendation I was easily and efficiently able to implement the time limits. I just added the size limits as well with tests so from the LDAP protocol side we should be all set with features and just need to fix bugs.
FYI the JNDI Core Provider will not honor size and time constraints even though the frontend protocol provider will. I'm not too worried about this since it's a nice to have with the JNDI core provider. When someone needs it we can look into it.