As it turns out, those two have different issues:
The Pantheon was a PEBCAK, I accidentally installed Google’s drivers from SDIO and those were overriding coolstar’s for ACPI/GOOG0006, the sensors device. It is now working on Windows.
The Redrix… I decided to test on a Fedora 43 LiveCD and… it doesn’t rotate at all there as well.
Then I found this (DriverIdentifier)[ Google Redrix Drivers ] from someone’s different Redrix, which shows the “[ACPI\VEN_GOOG&DEV_0006] Chromebook EC Sensor Hub” showing this device as installed.
Yet mine doesn’t seem to have this device at all?
Also found someone else with a (GitHub Issue)[ accelerometer is not working in redrix · Issue #879 · MrChromebox/firmware · GitHub ] that seems to be related, but it’s too light in details to be sure.
I’m attaching the cbmem log for the Redrix, as there might be something deeper going on.
cbmem redrix.txt.diff (307.7 KB)
edit: added more data in that GitHub issue above instead as it seems to be firmware issue by now.