ElasticSearch AWS plugin is a must to deploy on AWS?

We are planning to deploy our ElasticSearch on Amazon Web Services. I noticed that there is a plugin from ElasticSearch that allows ElasticSearch to use AWS API for the unicast discovery mechanism. ElasticSearch Cloud AWS.

My questions are:

• Should I use that plugin? or it is something nice to have but not required ?
• What is the effect of not using it?