We build a custom CSS file that includes the SCSS for the components we use as described in https://docs.telerik.com/blazor-ui/styling-and-themes/custom-theme#using-the-build-process-of-the-application
However, I have noticed that there are classes that only exist in the @progress/kendo-theme-default/dist/all.scss file.
One example is .k-overflow-auto which is used by the PDF viewer component without which the component does not display correctly and the paging functionality does not work.
This suggests it is not currently possible to use the customisation method to reduce the size of the delivered CSS as not all the classes will be available. Or have I missed something?