setVariableValueExt() ignored within On Variable Initialization when Load In Script = TRUE

Issue: When an applications data sources are set to load in script, attempting to set variables within On Variable Initialization ceases to work.

Workaround: Move setVariableValueExt() code to On Background Processing AFTER the data source has been loaded (i.e. DS_1.loadDataSource()).

Questions:

1. Is this expected behavior?
2. If we execute loadDataSource and then subsequently setVariableValueExt(), wont this refresh the data source twice?
3. How does this work in scenarios where we have multiple data sources with different subsets of the total amount of variables used by the application? (e.g. DS_1 contains 2 out of 5 variables, DS_2 contains 3 out of 5 variables and so on and so fourth. In this scenario we would not be able to set variable values until a sufficient number of data sources have been loaded).