When MP needs the xml file to display a particular panel, it checks to see if that xml file has been modified on disk, and reloads it if it has been changed.
The engine does not check whether the files have changed or not, it just loads them again when entering the window.
I have seen this mentioned before. My experience is that in most cases changed graphics are loaded without having to delete the cache. The one case that I noticed where changed graphics were not loaded was (I think) for themes, but I may have misremembered that.And do not forget that the pictures are cached, if you replace the picture, it may not be updated until it erases the cache.
Small skin graphics cached ... big not always ...My experience is that in most cases changed graphics are loaded without having to delete the cache.
While you in window al changes for windows skin ignored, when you reenter to this windowm its load skin again with all changes ...Well, I suppose something has to use up all of those MIPs; you cannot keep them for use later.