As of the Aruba VAN SDN Controller 2.8 release, the "pipeline-model custom" setting is supported on Aruba switches. The custom pipeline allows more efficient use of hardware resources (scaling) and multi-table OpenFlow packet processing.
If you haven't already, you can download the newest release of VAN here:
https://h10145.www1.hpe.com/Downloads/SoftwareReleases.aspx?ProductNumber=J9863AAE&lang=en&cc=us&prodSeriesId=5443866
I also wanted to offer an unofficial tool which might help in building custom pipelines for Aruba switches. This tool (attached as "pipeline.html" in pipeline.zip) is an HTML web page that uses javascript to construct properly-formatted JSON. It generates the format for both the VAN and RYU controllers which support Aruba custom pipelines.
Extended documentation for custom pipeline support in the VAN controller can be found here:
http://h20565.www2.hpe.com/hpsc/doc/public/display?sp4ts.oid=5443866&docLocale=en_US&docId=emr_na-a00003809en_us
Hope this is helpful!
