For our network, we set BABE EpochDuration to 1h instead of 4h. This is because validators are selected from a relatively small trusted set of keys for each epoch, and we found it was too long to join or leave the validators.
Reducing the epoch duration decreases security, but how much? Is there a serious analysis of the difficulty of an attack depending on the session duration?
[edit] Someone listed some chains from Polkadot Telemetry, sorted by epoch duration. It appears some of them which are not test nets are using 1h epochs. Epoc duration in Substrate ecosystem - Duniter-v2s - Duniter Forum