Please cast your vote to make it count. We will prioritize the features every release based on the demands and we do not have immediate plan to implement this feature since we committed with already planned work. So, this feature will be available any of our upcoming release.
If you have any more specification/suggestions to the feature request, you can add it as a comment in the portal. We appreciate your patience until then.
Also, we have achieved this requirement by creating two charts and collapse the visibility of primary axis of first chart. We have prepared a simple sample for this, and it can be downloaded from the link below.