Greetings from Syncfusion.
We have analyzed your query. As of now, we are not having spectrogram support. We have considered this smart label support for pie series and we have logged feature request. It can be tracked through our feedback portal below.
Please cast your vote to make it count. We will prioritize the features every release based on the demands.
If you have any more specification/suggestions to the feature request, you can add it as a comment in the portal.