How to Ensure Microsoft Editor Is Disabled and Basic Spellcheck Is Used in WebView2

[sauerben]

In WebView2, how can we programmatically ensure that the built-in basic spellcheck is used and that the Microsoft Editor (cloud-based spellchecking) is disabled to prevent any data from being sent to Microsoft servers?

In Edge, this can be configured manually via Settings > Languages > Writing assistance by disabling Microsoft Editor and using basic spellcheck instead.

However, I have not found an equivalent setting or policy in WebView2. Is Microsoft Editor disabled by default in WebView2, and is there a way to explicitly enforce this behavior?