Hi SP,
Trying to clarify your query based on my understanding
Point 1 // S4H needs new GL . Note that parallel accounting , document splitting are NOT needed . Only the concept of ledger (leading) needs to be implemented. Technical activation of new GL is needed in S4H as the data structure in S4H is similar to new GL in ECC.
For detailed migration steps , refer AC100 or the steps in IMG path
Point 2 // Refer note 1939592 for Pre-checks on asset accounting . Also note that , if you are on classic asset accounting in ECC , then all asset / depreciation postings need to be completed in ECC prior to migration to new asset accounting solution in S4H.
With regards,
Mrinal