Theta Z1 USB Data Transfer

I’m going a bit nuts here…

Just bought a Theta Z1, and I’m heading to Europe for a month. I’m worried the 350 shots I can take with the camera (shooting RAW) won’t be enough, so I’m looking for a way to offload the files on the go. I have tried a number of setups to offload the images using the USB plugin, but everything results in “USB DATA TRANSFER ERROR CODE: 001” showing up on the z1 screen, along with a beep.

Right now I have a USB-C to USB-A adapter, with a 128 GB USB 3.0 stick formatted with FAT32.

Anyone have any ideas? There doesn’t seem to be much/anything written up about using the plugin, and the user guide hasn’t been much help.

Has anyone successfully used this plugin on a Z1?

Thanks!