Background fanart that is applied automatically uses different scaling than background fanart that is selected manually. It seems the default background fanart that is automatically scraped uses the "Full Background" scaling level. Manually selected background fanart, either in Gemstone or BMT, uses the "Background" scaling level, which at default is a lower scaling factor than "Full Background". The suggested fix is to have the behavior the same between automatic or manual.
Background fanart that is applied automatically uses different scaling than background fanart that is selected manually. It seems the default background fanart that is automatically scraped uses the "Full Background" scaling level. Manually selected background fanart, either in Gemstone or BMT, uses the "Background" scaling level, which at default is a lower scaling factor than "Full Background". The suggested fix is to have the behavior the same between automatic or manual.