Hi there!
In the end, final configuration is a matter for each administrator to decide based on their knowledge of their network and their business requirements.
MLAGs generally provide the best redundancy for connections - in ONTAP you can create "ifgrp ports" that bind two physical ports together using LACP (or static), then create VLANs on those ifgrps, then place iSCSI LIFs on those ifgrps, and if one of the MLAG members went down, the iSCSI port would stay up without any need for the host to notice via ALUA.
Hope this helps - please feel free to ask any follow up questions!