With the newest NewsFeed Launcher version 20.0.0, third party icon packs now can request to be the selected icon pack.

This can be possible via a similar method as in another launchers.

Example code:

class ExampleActivity extends Activity {

    ...

    private void onApplyIconPackClick() {
        String selfPackageName = getPackageName();

        Intent request = Intent("hu.oandras.newsfeedlauncher.APPLY_ICON_PACK");
        request.setPackage("hu.oandras.newsfeedlauncher");

        ComponentName component = new ComponentName(
            "hu.oandras.newsfeedlauncher",
            "hu.oandras.newsfeedlauncher.customization.ApplyIconPackActivity"
        );
        request.setComponent(component);

        request.putExtra("package", selfPackageName);

        startActivityForResult(request, REQ_CODE);
    }

    ...

}