[mikeSiLVO]

Nothing in .DATA.xml will change when switching skins once those files exist - they're the bits of skin shortcuts which are shared between skins.

The thumb property is primarily for the image the user selects as icon image (as $INFO[ListItem.Icon] will grab the thumb if its there before using the icon - so the user choice is always respected). Backgrounds are best handled with Skin Shortcuts inbuilt functions - https://github.com/BigNoid/script.skinsh...grounds.md - which allow setting a range of backgrounds to choose from, using playlists as backgrounds, default backgrounds for menu items and integrates nicely with the background options Skin Helper provides; or with a custom property.

It's probably also worth having a fallback background within the skin itself, if a menu item doesn't have a background defined in the overrides.xml - which custom menu items won't if coming from another Skin Shortcuts-utilising skin.

Silly me

I should have RTFM! *FacePalm*