We were about to embark on doing a full environment upgrade/migration to IDM 4.6 on eDirectory 9.0 (from 4.5/8.8.8), but with the release of 4.7 and 9.1 we are rethinking our approach. We have the need to get some eDirectory 9.0 servers to handle vendor software that will only connect to LDAP over TLS. The question is, is there any reason not to migrate the root master and some LDAP servers to eDirectory 9.0, wait a bit for 9.1 to have some patch releases, upgrade those to 9.1, then after that, actually migrate the IDM server to 9.1 and 4.7.

We would likely be running the idvault server on eDirectory 8.8 for a few months while the rest of the eDirectory servers are 9.0/9.1.