.NET SDK Support in Business Objects 4.1

Dear all,
I am working on a client request regarding the possibility of integrating Business Object 4.1 into a .Net portal. Documents I found reflect it was still supported in all the way till 4.0 SP2 but I couldn't find any document regarding 4.1. It would be much appreciated if anyone with prior experience can provide some directions.
Thank you very much in advance.
Sincerely,
Justin