I know that when doing BL I should search by ID using collectionAccess.objectID(idString). What's the flex equivalent? Flex doesn't have a collectionAccess module.
In Flex you may use modules.dataStore() and findById() method as it is shown here: https://devcenter.kinvey.com/rest/reference/flex/reference.html#data-store-module
There is no need to convert the id to objectID as in BL collectionAccess.