Java JNLP Launcher.jar not being redirected to port 443

I'm not sure you can use three expressions separately as you appear to be doing, I'd try this instead;

 {@http://mydomain/ufs:80@https://mydomain/ufs:443@ @http://mydomain/ufs:8080@https://mydomain/ufs:443@ @http://mydomain/ufs@https://mydomain/ufs@} 

If you still get no luck I would suggest you do a tcpdump on the F5 and capture the server responses on the 'internal' VLAN, which should be unencrypted and will hopefully give you a better idea of what the server is sending back.