For normal/standard functions, there is a provision to cache output for given input combinations. It can be done by clicking on "Set default values" for that function
If it is set, computation done in function would not run again if same input is received within 1. a document OR 2. a map
This is very much useful for something like SQL Lookup.
But such option does not seem to be available in User Defined function. I have built a User defined function which encapsulates 5-6 Cache lookup and few string functions.
I wanted to cache for this User defined function, but these options (radio-buttons) are not available.