Antarctica/Casey is currently DST-free but has (very) historic DST until earlier this month.

The generated module has

sub has_dst_changes {0}

That should be a 1 despite current TZ span end of Inf as it has the historic outrageous ±3 hours twice-annual sleep-cycle disruptions (ouch) listed for prior years. (Pod says current, future, or historic.)

@autarch guesses this is a generator code issue.