AC88U - Dual WAN 4G and AMTM Packages - Possible together?

[systematic]

Hi guys,

I currently have a USB storage device plugged into my 88U and its being used for some AMTM packages. I would also like to use DUAL WAN to flip to a 4G dongle. Im assuming that this is not possible as I am already using the USB port?

 

[systematic]

Damnit ignore this - I just saw the second USB port!! Dang. I was under the impression I only had one port

Im assuming I put the DONGLE or the Storage device for AMTM scrips in either USB port right?