Completely agree, use Elasticsearch the companies offering. After being bitten by previously no VPC support for AWS Elasticsearch (though supported now), and blue-green deploys even with a small configuration changes (used to be security policy updates even) that can take 12-24 hours I generally don't recommend AWS Elasticsearch.
Since I worked for Amazon and saw how the sausage was made, I am reluctant to ever use AWS again. Random grab bags of teams using all different tech with different coding standards and methodology. Jerry-rigged micro-services turned into APIs through total object instantiation rather than efficient mutable updates.
Also, based on the previous in incident regarding search guard copying xpack code, I am guessing that there is maybe some intent to get AWS to just buy out ES , thus carving a wonderful exit. Just thinking!
https://twitter.com/kimchy/status/1182745675617824768