how to setup persistence to concatenate jvmRoute with JSESSIONID to generate final SESSIONID

Since jvmRoute is already appended to the JSESSIONID by Tomcat you can just consider it as part of the JSESSIONID. The irule in the linked page should work out of the box.

Note that setting the jvmRoute in Tomcat server.xml has no added value from a universal persistence perspective. It only appends a string to the JSESSIONID but does not make it more unique.

For one client I created an irule that only use the jvmRoute part of the JSESSIONID to select the backend. It probably as slightly more processing overhead but limits the number of entries in the session table. However, unless you have extreme numbers of current user sessions I would recommend using the example iRule from the page you referred to.