Hey, I did some changes in skin files yesterday and found that just re-read screen where is changed skin file. I'm not sure whether it is the intention of the creators of the GUI or is it a coincidence that 1.2Beta behaves as follows. It is a strange.
The behavior of the MyRefresh is to reload the xml's without restarting MP or going to another screen, or reloading the skin from the GUI (if you change the references.xml you would normally have to restart MP) .. The plugin doesn't make easy changes to any graphics changes if you edit the graphic file, only if you change the referenced file (most cases - unless it is a newly created graphic file and not yet preloaded in the cache). The pre-cached graphics would still be used until you stop MP, delete the cache file for the skin, and restart MP, renewing the cache.
Hope that helps understanding the use and limits of the plugin.