I am learning to implementing REFWRITE in my current project, and have found the "Reference type" to be very clunky.
ie: go to System Configuration, click on Memory Configuration, scroll down list to find desired data type, check number, cancel the System Settings, Type number into box...
What I ended up doing: Take the structure name, and assign a symbolic constant to the same name. That way if you use the structure name without the index, you get the data type number.
The feature request would be: could you make this automatic? (when I create a structure you automatically make a symbolic constant with the same name as the structure).