The FilterControlWidth applies to the filter in the grid header cell, not to the context menu.
To be honest, width settings for the context menu have not been exposed as settings.
Nevertheless, I am attaching here a sample that uses a CSS override to change the menu elements width. I must note that this may not suit all use cases, and cannot be really dynamic. Such a workaround is not ideal, because it is a hack, since the excel-like menu does not have a provision for changing its size.
Here are the key points:
- The OnPreRenderComplete event is used to add a CSS class to the menu.
- The RenderMode is Lightweight because it allow for more CSS customizations.
- A dozen lines of CSS override the built-in menu settings so that they set the width to a hardcoded value (500px in the sample).
I hope this helps you move onward.