Is there a custom NDS ROM that lets you configure WFC (not a game)?

Yes, there are custom NDS ROMs and homebrew applications that allow users to configure Wi-Fi Connection (WFC) settings. These ROMs typically include modified firmware or custom software that enables enhanced connectivity options or features not available in the original Nintendo firmware. However, it's important to note that using custom ROMs can violate Nintendo's terms of service and may lead to unintended consequences, including potential bans from online services. Always exercise caution and be aware of the risks involved.