Can I use the USB dongle in this Aria 90B set with other devices like my other headphones?
The dongle DG10 in the Aria 90B set can only work with the headphone in this set, you can not use it with other devices.
But you can use the headphone with other devices, please refer to this link to know how:
How to Enter Aria 90B Into Bluetooth Pairing Mode / Reconnect