Dual stack split: Use existing Java stack?

Hi,

I am going to split a BW dual stack (SAP NetWeaver 7.0 EHP1) and am wondering if I can use an existing Java stack?

I thought about using the "Keep DB" option and instead of installing a new Java system and then connect a stand-alone Java stack through the Template Installer in NWA.

Does anybody know if this is supported by SAP and in case of yes, where I can find documentation about this procedure? E.g. which release dependencies and support packages on java side are needed (now and after upgrading the remaining ABAP stack to 7.4)?

Best regards,

Sebastian