USB drive size limitation
Today it's very hard to find a USB drive less than 8Gb in a store. If you need a Bootable USB with MS-DOS, or for some other reason, WinToFlash can limit total capacity of the physical storage device. This option won't change a firmware in a USB drive controller, it limits the size of the USB drive inside the WinToFlash partitioning core. You can always undo this by wiping the USB drive with WinToFlash and format it again with Windows.
You can set the limitation by sectors, bytes, megabytes and gigabytes.