You're correct I just checked this issue. Simroute is an old site without recent update. The problem is fsx accepts flight plans in xml file format but simroute, generates flat file format. One could write a small program to convert from one format into another but not sure if its that worth!

btw simroute can create flightplan with SID and STAR if you goto Generate Routes   link but you've to manually enter other waypoints for the route itself or copy paste the route from (http://rfinder.asalink.net/free/ ) and select your choice for given SID and STAR options....works fine for other aircraft lvld 767etc