Hi John,
Thanks for the reply. Here's why I was thinking I could move to flat files:
I've noted that when creating ipa-replia servers, I have needed to specify '--setup-dns' along with a forwarding option if I wanted the server to configure named-pkcs11 to use the bind backend. Otherwise, named is not set-up and the ipa-replica server handles all other functions (authentication, mainly) just fine.
My thinking is that I would have 2 IPA servers that would still use named pointed at bind as they were set up, but my other ipa servers I would reconfigure named to use flat files, with the 'master' pointed at the 2 IPA servers I had left alone.