I'm not sure if something else is interfering with the addon but the scale bar is grayed out and inaccessible for castbar, minimap, action bars, and chat, so I can basically only resize the unit frames. This happens with no other addons active so I'm not sure what could be causing it if the scale feature should be usable?

The new Version (v0.4.0) opens up more customization options. Some are still deactivated while they are worked on.