In the migration guide, when describing ability to partially migrate applications from legacy security subsystem to Elytron, please provide clear description of limitation, that applications, when using different security subsystems, cannot invoke each other (e.g. EJB in ejb-jar using Elytron cannot be invoked from servlet in war using legacy security).

See Darran's comment here: https://issues.jboss.org/browse/EAP7-482?focusedCommentId=13400820&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13400820