When several absolutely identical USB devices are plugged into your computer, you can choose which of devices should be shared and which should stay unshared. By sharing a device, you make it available for redirection to remote computers.
To help distinguish between identical USB devices, USB Redirector RDP Edition shows the port number where USB device is plugged or device's serial number (if exists). When you share a device, USB Redirector RDP Edition remembers it's USB port number (or serial number). The device will stay shared (even after replugging) until you unshare it.
Please note, if you re-plug a USB device which does not have a serial number into another USB port, it will look to USB Redirector RDP Edition as another device. There is no way to distinguish between devices other than by USB port number or serial number.
For even better experience, you can assign a Custom Device Name to each of your devices.
You can share a dongle plugged into 1-2 USB port. The other dongles plugged into other ports will stay unshared.