To create a uefi usb boot device with wim file bigger than 4GB (the limit of the fat32 file system) you need to split the wim file in swm files with this command:
Dism /Split-Image /ImageFile:E:\iso\sources\install.wim /SWMFile:E:\iso\sources\install.swm /FileSize:4096
After that you can copy the files to the USB device
