RAP Node Extensibility for Unmanaged BO

[michael_zinncker]

Hi Experts,

Target System: On Premise, S/4 2023 FPS01

let's assume we have a released, extensible, unmanaged RAP BO like R_SalesOrderTP and would like to extend it for new nodes as mentioned in here: Node Extension - SAP Help.
CDS extension works quite well, but as soon as we try to add Behavior for the newly added Node in the Behavior Extension:

extension using interface i_salesordertp
implementation in class zbp_x_ndext_r_salesordertp unique;

extend behavior for SalesOrder
{
  association _myNewNode { create; }
}

define behavior for zr_salesorderndexttp alias MyNewNode
late numbering
( lock, etag, authorization ) dependent by _SalesOrder{
	field ( readonly ) SalesOrder;
}

the following error occurs: "unmanged/extension/define behavior" is not supported in this ABAP release. That's quite unfortunate, but i understand that this kind of feature is not supported. Yet?
I do know of the following Feature Matrix where it is mentioned that Node Extensibility is not supported for unmanaged BO. "Enable the original RAP BO for node extensibility" -> even though the Extension on CDS level works quite well and it seems the only missing part is that we are not allowed to add Behavior for new nodes.
Am I right in my assumptions and Is there some kind of roadmap and/or target releases where this feature will be supported?

Thanks in advance for your help and information!

Best,
Michael

[michael_zinncker]

Maybe @Andre_Fischer has some information about features on a roadmap?