Overriding layout options in subtheme

I would like to simplify the ui in layoutbuilder by reducing the layout and style options to a minimum set.
I created a subtheme.layout_options.yml and a subtheme.ui_styles.yml in the subtheme folder and made some changes. But that did not work, all options are still available as declared in the files from the parent theme.
What am i missing here? Thanks in advance for any hint.