Thanks for sending the class to me Yaniv.
Life is always easier when you don't have to guess what is happening.
The 2 options list above are not really options, but rather the steps you should take when defining any type of index for Cache SQL Storage. Defining the Index def helps us correctly report info to external databases, but it is the map in the storage that the query optimizer is looking for, so #1 is required for all types of indices.
Here is the property and index