This is about running 8BitDo's Firmware Update tool for Windows in Wine. It can be used for updating newer 8BitDo devices that may not be supported by fwupd on Linux.
This tool needs Segoe UI Symbol font, on Arch this font is provided by ttf-ms-win10-auto package. For other distributions there is install script.
You will have to let Wine access device's HID interface for updating the firmware. Most importantly it should be a boot HID interface (exposed when device is in bootloader mode, often referred to as "manual update mode" or "advanced mode"). It is also worth adding the Product IDs for HID interfaces that are exposed under different conditions (for example, Ultimate Bluetooth Controller's receiver exposes a HID interface when controller is not connected), so the upgrade tool can detect it and automatically put it in bootloader mode for upgrading the firmware. You can use lsusb to