We still have a few OS 2.3 left (even though we do not officially sell version 2.3 any more). If you need, you can send a support ticket and arrange to purchase a version 2.3, which still works with your existing expanders.
As I said many times on the forum, if this is a support question that you need quicker response, please send a support ticket. The forum is not checked on a regular basis, and for all support questions we need to verify your order number and purchase date, so leaving a question like this on the forum will likely delay the handling of your question.