Framework doesn't even develop their own firmware; most of the engineering in PCs is done by Intel/AMD/ODMs/IBVs. The whole ecosystem is based on vendor support not datasheets.
Firmware is not preventing Framework or anyone from offering a repairable laptop. Firmware also doesn't matter once the kernel is loaded. We need the datasheets.
I was under the impression that the firmware is responsible for loading the ACPI tables but the OS takes over and runs the code in its ACPI VM once running.