Manjaro and Garuda have a known issue that PureBoot isn’t able to boot them automatically. It’s possible to boot them manually from the recovery shell: Librem 11: SeaBIOS/Coreboot does not recognize keyboard. PureBoot does not boot USB - #19 by jonathon.hall
Most other distributions boot from USB normally. Arch and Manjaro both appear to have a problem in the latest kernel’s i915 module, we had to roll back to a 6.5 kernel (noted in that thread).
PureBoot also requires an unencrypted /boot partition. Some distributions default to this, but others do not; partition manually if the distribution defaults to something else.
If you plan to use automatic screen rotation, you will want the accelerometer mount matrix as well - https://source.puri.sm/librem-11/librem11-base/-/blob/pureos/latest/default/61-librem-11-accelerometer.hwdb. (Linux lacks support for getting that from the firmware via ACPI currently, so we added the quirk in PureOS.)