Moving files from one volume to another extremely slow

I have attached a drive with video files to one of the usb ports on my EX4100. I want to transfer files from that drive to the Public/Shared Videos folder on the main array volume. It is incredibly slow using finder on my Mac. Is there an app that can do this natively on the EX4100 without having to send large amounts of data across the network and back? I’m on Mac OS Catalina

@dwiener install the USB Backup app and perform a COPY USB to NAS backup to the Public Share. I suggest to disable “Mobile & Web Cloud Access” on the USB share after attaching the drive for best performance.

Thanks. I’m trying that now, However it only lets me select a limited number of folders, and only the root folder of the destination (i.e. Public, and not Public/Shared Videos