Unsupported messaging subsystem configuration attributes silently ignored

When there is an unsupported configuration attribute in standalone.xml, it is silently ignored and deleted from the configuration without a single warning the first time the server writes the configuration back to the disk. Sample piece of configuration (in standalone.xml):
<connection-factory name="RemoteConnectionFactory">
<transaction mode="xa"/>
<connectors>
<connector-ref connector-name="netty"/>
</connectors>
<entries>
<entry name="RemoteConnectionFactory"/>
</entries>
</connection-factory>

Transaction mode is unsupported in an ordinary connection-factory. It must be pooled-connection-factory.