we run EHP7 with classic ledger + oracle db and have a upcoming S/4 Project.
1) The plan is it, to migrate to the HANA Database and S/4 Enterprise Management in one step. Therefore we need to implement the new GL, since this is mandatory required for S/4.
2) Is it possible or rational to implement the new GL+ HANA DB + S/4 HANA Enterprise Management, without any new GL functions and implement the functions like document split or the ledger solution in the second step ?
The Goal is to start the S/4 conversion project soon and to keep it simple. In my oppinion the configuration and implementation of the new GL functions would slow down this conversion and delay the project.
As per the roadmap from SAP, if you are migrating from Classical GL to S/4HANA, you will have a limited functionality of new GL and you will not be able to use the functionalities like Document Splitting etc in future as per the product functionality today. This is an ask by many customers and is a probable roadmap for SLT services for 2017 Q4. But as of today, you cannot utilize functionality like Document Splitting etc as a separate project post migration to S/4HANA. In case you have a business case for document splitting, than you have to first migrate to the same and than plan for a separate migration to S/4HANA as a new Project.