@RL_Dane I should note that building lbmk in OpenBSD is currently untested and assumed broken; certain utilities handled by lbmk may still compile, so for example it may be possible to use the ./mk inject command, though the latter is not required on X200 images anyway (no additional vendor files needed).
Simply running flashprog is supported in BSD however. I have BSD lbmk testing on my long-term TODO plans; perhaps this will be covered in my next audit (expected to begin in early 2025).