Similar to ig's proposal below, I would collect the lines belonging to a list and then call a sub that processes the lines of the list.

...
$tab++;
my @list;
for my $line (@{$section}) {
    my $line = convert_string($line, $line_magic);
    
    if( $line =~ /^[*#]+ / ) {
        push @list, $line;
        next;
    } else {
        process_list( @list ) if @list;
        @list = ();
    }
    line($tab, $line),     next if $line =~ /^</;
    ...
[download]