vt(4) is the default console for UEFI boot [1], and the bitmapped kern.vt.spclkeys sysctl has been replaced with individual kern.vt.kbd_* enable sysctls.
PR: 193710 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193710
Submitted by: wblock [1]
MFC After: 3 days
Relnotes: Yes