shared storage with local indexes?

I'm trying to figure out how to have multiple Dovecot servers for high availability after replication goes away. The obvious solution would be some kind of shared storage, but the docs have all kinds of warnings about possible data corruption.

It seems like Maildir is the safest mailbox format for shared storage, but even with Maildir there are warnings about the possibility of corrupting the index files. Would it make sense to use shared storage for the maildirs themselves, but use the INDEX option in mail_location to store index files locally, and have separate index files for each Dovecot server? That would take care of the potential for index corruption, but what other strange problems would it cause?

Andy