Dear Customer,
Thank you for contacting Syncfusion support.
As given in the provided code snippet, you can hide the legend in "drillStart" event of the TreeMap component. We are unable to reproduce the performance slowness with 5000 data. Please find the sample, in which we tried to reproduce the reported performance slowness, below.
https://stackblitz.com/edit/react-gw6pmc-8fvtek
We suspect that the performance slowness is due to the data source that you have used in your application. Please modify the above sample or share the data source to reproduce the performance slowness. It will be helpful for us to analyze and assist you further.
Regards,
Indumathi R.