any form of USB, is just for power-on the device
but can be used as Powerline (ethernet over powerline).
I do agree, if you can afford better (like hAP ac Lite), don't buy SMIPS, or maybe stick to an older ROS version.
I do run it on 6.44.5 and 6.45.6 ... and it works great as my VPN and VPN-TURN server, I have even the web proxy server enabled, which gives faster response in VPN over satellite connections. (tcp session reuse)
It's also a very cheap way to have multiple AP's in house, or for your ESP32/Raspberry Pi/Arduino experiments. (I use it in repeater mode at Coderdojo workshops)