Hello,

I am happy to announce that the custom cell editors feature of the Spreadsheet is now available starting from v21.0.0:

https://www.telerik.com/kendo-angular-ui/components/spreadsheet/custom-cell-editors 

Regards,
Slavena
Progress Telerik

Hi,

The custom cell editors feature of the Spreadsheet component is still not part of our development plans and we are still monitoring the customer demand for it.

With the above being said, in case the implementation of this Spreadsheet feature is very urgent for your project, we offer a Feature Acceleration program, which is suitable for cases where a feature or enhancement is crucial to an application's success, but is not scheduled to be available by the time the application is completed.

Feel free to reach out if you have interest in exploring this option further at any time, and I will put you in touch with our Professional Services team to discuss your exact requirements and possible timeframes.

Regards,
Zornitsa
Progress Telerik