Complex Pre-Validation using OIC for Bulk upload using Smartsheet

Summary:

We have a requirement where user would upload bulk items using smartsheet for different usecases to create/update items where we would like to do all complex pre-validations before item creation/item update using OIC and based on OIC output if pre-validation fails then item creation/update shouldn't happen else if it's success then item creation/update should happen.

Found Item Bulk Load Event in OIC but it triggers after item batch processes the records and returns back to OIC with request id which doesn't help to do any pre-validations.