How do i update element properties by plugin in builder

[Tim-Wapenaar-Fenetre]

Im passing some settings to the builder component which I want to use as default for elements. I would guess a good place for that would be by a plugin.

In the next example, i want to set the accept property of the fileElement with my list of allowed file type.
But this does not update those properties.

export default function fileDefaultsPlugin() {
	return {
		apply: "FileElement",
		setup(props: any, context: any, component: any) {
			const form$ = component.form$.value;
			if (form$.builder) {
				const formSettings = form$.builder$?.$attrs["builder-settings"] || {};

				return { ...component, accept: formSettings.allowedFileTypes };
			}
			return component;
		},
	};
}

And trying to set the value with props.accept.value = formSettings.allowedFileTypes results in a cannot set a readonly property warning