I would like to be able to set the Id on any Blazor component for automated testing purposes.
If you need something different than automated testing selectors, please add your use case in the comments.
For automated testing, you can cascade selectors through a parent element (e.g., a div or span) that has the desired attributes (be that id, class, some data-* attribute, etc.). Adding ID parameters to Blazor components can easily make them brittle because they can be repeated and included in arbitrary hierarchy easily - that's the core concept of a razor component - so such IDs need to be unique, which defeats the predictability you will need for testing.
If you are interested in testing with Selenium, you may find useful this request: https://feedback.telerik.com/blazor/1513117-translators-for-selenium-testing-for-the-telerik-ui-for-blazor-components. If so, Vote for it and Follow it so we can know there is interest, and so you can get status updates.
You can also Follow a separate enhancement for the Grid Command buttons here : https://feedback.telerik.com/blazor/1463164-id-attribute-on-buttons-telerikbuttons-gridcommandbuttons-etc