I believe this issue could (or should) actually be closed as Resolved, and new issues be filed about the issues that are still present.
AFAIU, Francis worked on adding support (see commits linked as a comment in 2014 https://issues.jenkins-ci.org/browse/JENKINS-4995?focusedCommentId=206750&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-206750).
People have rightly reported various issues above (infinite loop, etc.?).
But then I also see people providing workarounds.
In other words, I believe closing and having people report more specific issues would provide clarity and make this more actionable.
I think I'll close this JIRA in the next days if people don't disagree. *Again*, this is not to say things are great and work perfectly already. The goal is actually to target more a win-win: better clarity, so the current EC2 plugin maintainers (I'm not one) can more easily understand what needs to be fixed and help users here with issues.