I'm using a regex-principal-transformer using the default standalone-full.xml configuration provided in the standard wildfly distribution (using Wildfly 26).   The pre-realm transformer is applied to the security-domain "ApplicationDomain".  I'm expecting it to handle transforming the principal name for all usages in the security-domain for both authentication and authorization.  The pre-realm transformer doesn't work as expected, where initial contexts with a different principal is transformed to the correct principal fails the authentication step.  In looking at the stack trace output it seems the authentication is still being done using the original principal name.
See the trace Ouput: Trace_Output.txt