While updating our App SDK to version 4.x, we cannot set eVars/props
within the app. We need to use contextdata variables and then map it to
variables using processing rules. We do not want to miss the data form
users who are not updating their app instantly. So we need to create a
unique rule for each variable (e.g. if prop1 is not set, overwrite prop1
with contextdataprop1). After setting the rules for checking each
variables, we feel like we will not have enough rules for doing custom
process...