Async servlet (async-supported=true) using with log4j2 breaks the async chain because it does not support async.
All element in the chain must support async in order to use async.
Implementation is required to support async servlets(async-supportd=true) it may be automatic or configurable initialization. ( this Issue may be dependent on the issue https://issues.apache.org/jira/browse/LOG4J2-270 )
Initialization and de-initialization of the logger must be configurable in the java code/config files, to re-load the logger with different properties, that will help the application to reduce re-start burden when it need to use different properties.