@mttaggart Sorry for the German. Looks like dot list files in
/etc/apt/sources.list.d still work with Debian Trixie, but I wonder why I could not find an example of a dot sources file for the Vivaldi repository. Due to AI and commercialization search engines do not help much. To set up Vivaldi stable made me sick too with all that built in consumer stuff. At least it's only my secondary browser and a lot of things can be turned off.
@Vivaldi