foreach my $recid ( reverse sort %SeqOrders ) ...

##</code><code>##

$ perl -MData::Dump -e '%x = qw{a 1 b 2 c 3}; dd \%x; dd { reverse sort %x }'
{ a => 1, b => 2, c => 3 }
{ 2 => 1, a => 3, c => "b" }

##</code><code>##

my %rev_seq = reverse %SeqOrders;
for my $recid (sort keys %rev_seq) {
    ...
}