Just wanted to update this thread to say that now another T480 user (the T480 is a very similar model to my T480S) using the release builds of libreboot (as of 26.01 RC1) also has the entries missing from the ACPI tables. That discussion was here https://codeberg.org/libreboot/lbmk/issues/394. So this confirms that I'm running a standard libreboot, rather than a bad build.
Do you think there is any way to avoid the underclocking issue with Xen on such devices/firmware?
