Hello,
For this kind of scenario, we are not able to do some test cases related to this. It would be best if you can test it from your side. But mostly the USB port for RUT955 is used for Memory Expansion, Samba Sharing, and Modem Dongle. Lastly, when SD Card is inserted we are accessing it through LAN cables or WiFi network in partnered with Samba.
I hope it helps.
Regards,
Mellow