pmbootstrap kconfig check --file is broken

$ pmbootstrap kconfig check --file ~/something
[15:36:11] ERROR: check_file() got an unexpected keyword argument 'force_anbox_check'
[15:36:11] See also: <https://postmarketos.org/troubleshooting>
Run 'pmbootstrap log' for details.

since !1916 (merged), the --file flag is broken. It's my fault; I did add a test in the testsuite for it, and probably didn't check because of that :S. That was visibly a bad idea.

Since it has been broken for more than a month (since March, 24th) but nobody apparently noticed, I'm wondering if the feature is actually used at all. That's why I'm wondering what the best course of action would be. Should I work on a fix (should be fairly simple) or remove the flag altogether instead?