Did you see that the THETA X can shoot video at 5.7K? What resolution of the images do you need?
Can you take video and then extract the frames?
https://devs.theta360.guide/ricoh-launches-new-theta-x-360-camera/
The THETA V used to have feature for Google Street View 5.4K video at 5fps. The frames were automatically extracted and send to GSV.
If this type of feature existed for the Z1, would it meet your requirement? If so, do you need the file to be transferred by the USB API?