This limits the siebel automated deployments and introduces manual intervention step.
Searching on support web reveals that Oracle has accepted the system limitaion and created a BUG for it in 2014 however no update has been provided till yet.
The manifest is now stored in Repository tables and therefore would be migrated with the rest of the Repository.
With the way Open UI Manifest migration is implemented, there does not appear to be a SIF export; yet, it migrated with the Siebel repository. Thus, it seems there is no way to generate a SIF for the manifest data. Siebel Tools Object Explorer Screen shot that lists the S_UI_* tables and shows project name: "Repository Table" that proves dev2prod will migrate these.
Customer requested an enhancement on being able to incrementally migrate Manifest information without doing a full repository migration, such as using a .SIF file.
Bug created : BUG 19469254 - OPEN UI MANIFEST MIGRATION BETWEEN ENVIRONMENTS IN .SIF FILES
Solution :The only way available now is to manually keep track of the manifest changes and import them through UI with every release.
To make it a bit easier to identify the custom records one search with : [Record Source] = 'Customer'
This will return only the custom created manifest records.