I think the OP [kirk] already solved this issue.
Because someone already pushed the 60-sensor.hwdb config for the Ubook X into github, before I entered the Freebook config in the same github file:
# Chuwi Ubook X (CWI535)
sensor:modalias:acpi:MXC6655*:dmi:*:svnCHUWIInnovationAndTechnology*:pnUBookX:*
ACCEL_MOUNT_MATRIX=0, -1, 0; -1, 0, 0; 0, 0, -1
# Chuwi Freebook N100
sensor:modalias:acpi:MDA6655*:dmi:*:svnCHUWI*:pnFreeBook:*
ACCEL_MOUNT_MATRIX=0, -1, 0;1, 0, 0;0, 0, 1