50-cloud-init.yaml, optional: true - will the network interface get initialized if it gets online after the boot sequence?
Solution 1:
Without the optional: true statement, ethernet network interfaces that are not completely ready can add an additional 2+ minutes to the boot time.
With the optional: true statement, the boot cycle will continue, without delay, and it'll bring up the ethernet network interfaces when they're ready.
Unless you've got a specific ethernet network interface that MUST be completely operational for other services to properly start, go ahead and add this statement to the other ethernet interface stanzas.