NIM: Used for sysupdates and system/eShop title downloading. Also does eShop account network requests via SOAP. NetUpdateSOAP is targeted by the server config. With your own config which specifies a different new_url for NetUpdateSOAP, you could use network sysupdate installation to install any system titles you want that are newer than the currently installed ones(see web/NetUpdateSOAP.php). Be very careful with that, your system may brick if you install system titles(NATIVE_FIRM mainly) from the wrong model(Old3DS/New3DS). You could also install old titles from eShop with this when the title isn't installed currently, even with downloading all required files from your own server if needed.