Before you begin, I think it would be a good idea for you to review Solution ID 200986393. The jist of their note is, and this applies to Boomerang just the same, you should be careful to use this process specifically for custom objects. Also be mindful of major specification changes between releases as well as architecture changes (such as betwen ERP 8.0 and EnterpriseOne 8.9). I can add that you should capture all object dependencies before proceeding down this path, but once you have your requirements, it should work perfectly fine.
Although I did not attempt an OMW transfer from 8.11 to 8.12 (need a working system outside of a sandbox area for that), I was indeed succesful in my attempt to transfer from 8.11 SP1 to 8.9. In theory , it should work from 8.11 SP1 to 8.12.
This process is, for the most part, documented in Document ID OTT-03-0025. Unfortunately, this document is apparently no longer on the Customer Connection. I can't believe it, but I do have a hard copy of the document from years ago. There are a number of ommissions, but with sufficient CNC knowledge you can fill in the gaps. I've added a few of my own additional steps to their process, as you will not be successful if you simply follow the steps in OTT-03-0025 to the letter.
The process is (assuming you use the standard pathcode and environment naming conventions, e.g. DV811 & DV812):
1. Create a database user account in the target JDE release database. For instance, create PSFT in the 8.12 database and grant the appropriate role to PSFT, such that it will have the same access as the JDE user in the target release.
***It is important that you set the password to be the *same* as the PSFT user in your 8.11 release. If you fail to do this, you will see thousands of database login prompts when you attempt a transfer from 8.11 to the target release. You will also see a few of these when you attempt to add OCM mappings in the System - 811 OCM table.
2. Create multiple data sources which point to your target database. These are specific to the target environment (e.g. DV812) and include System, Control Tables, Central Objects, Versions, Data Dictionary and Object Librarian datasources. Yes, you will see two "System" datasources in the the Database Datasources Application. This is fine because your clients and servers will point to the proper System Datasource in their JDE.INI and JDBJ.INI files.
3. Create a path code in the source release which mirrors the target release pathcode. You should include the proper deployment server name and path.
4. Create an environment for the above path code. This does not need to be an environment complete with all OCM mappings, simply an environment which points to the pathcode. For instance, if you are transferring from DV811 to DV812, create an environment in your 8.11 release named DV812 and point to the DV812 pathcode you created in the previous step.
5. Create *PUBLIC active OCM mappings for the F9860, F9861, F9862, F9863, F9865 and F983051 tables. (I also included Central Objects tables in the OCM.)
6. Use the Release/Data Source Map application (P00948) to define the release value for the Data Sources in step 2.
7. Use the Release Compatibility Maintenance application (P00946) to define the data sources and target release values.
8. Create OMW Transfer Activity Rules to transfer from the source environment to the target release envrionment.
9. Create OMW Allowed Action Rule to enable transfer from the source environment to the target release environment.
10. Create new status code to transfer project to the target release.
11. Logout (to clear your cache) and back in again. Test your transfer process using OMW. If you see errors, check for the source and examine the previous steps for anything you might have missed.