package Foo::Bar;
sub import {
    my %handlers = (
        DEFAULT_XFR => \&set_xfr,
        NO_LOG      => \&disable_logging
    );

    my @args;
    for my $i ( 1 .. $#_ ) {
        push(@args, [ $_[$i], $i ]), next if $_[$i] eq 'DEFAULT_XFR';
        push(@args, [ $_[$i], $i ]), next if $_[$i] eq 'NO_LOG';
    }
    # two loops because we don't want to splice @_ while looping over it
    foreach my $arg ( @args ) {
        if ( exists $handlers( $arg->[0] ) ) {
            $handlers( $arg->[0] )->( $arg->[1], @_ );
        }
    }
    Foo::Bar->export_to_level( 1, @_ );
}

sub set_xfr {
    my $index = shift;
    if ( defined $_[$index + 1]  and $_[$index + 1] =~ /^([A-Z]\d{4,5})$/ ) {
        $Foo::DEFAULT_XFR = $1;
        splice @_, $index, 2;
    } else {
        $Foo::DEFAULT_XFR = 'H00293';
        splice @_, $index, 1;
    }
} 

sub disable_logging {
    # same concept;
}