We have this wiki page already:
To find a reasonable answer to the original question:
Should (lesser) Adversaries with Physical Access be part of the Threat Model of Whonix / Whonix-Host / Kicksecure?
Answer:
Lesser adversaries capable of pressing well known keys on the keyboard should be unable to compromise the machine such as by circumventing the screensaver.
(Adversaries incapable of deploying self-written firmware trojans, miniature cameras, laser microphones, hardware-based keyloggers, TEMPEST.)
Does that sound reasonable?
Specifically, resolving Screen Locker (In)Security - Can we disable these at least 4 backdoors? seems realistic.
Is SysRq tamed enough currently?
Security discussion summary:
System Recovery using SysRq Key
If not, please summarize/bump here: SysRq (Magic SysRq key)