Fun with pos()

This rewrites the file after each change, then reloads from that file for the next change. The current position in the file is kept in the variable $pos. This stops the overlapping problem you were having.
I'm using Path::Tiny because I get yelled at when I use File::Slurp.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11145971
use warnings;
use List::AllUtils qw( nsort_by uniq );
use Path::Tiny;
use Text::CSV qw( csv );

my $csv = <<END;
whitelist entries,Noun,access list entries
IP whitelist,Noun,IP access list
IP whitelist entries,Noun,IP access list entries
whitelist,Adjective,allow
whitelist,Noun,access list
whitelist,Noun,access-list
whitelist,Verb,allow
your whitelist,Noun,your access list
your whitelist,Noun,my permission list
your whitelist,Noun,thy permission list
your whitelist,Noun,his permission list
your whitelist,Noun,her permission list
your whitelist,Noun,its permission list
your whitelist,Noun,our permission list
your whitelist,Noun,your permission list
your whitelist,Noun,their permission list
END

my $target_file = path( '/tmp/d.11145971' );
$target_file->spew( <<END );                    # FIXME for testing
a. this is some whitelist test
b. for IP whitelist testing and your whitelist
c. line with no replacement
d. with whitelist and IP whitelist entries and IP whitelist entries ag
+ain.
e. this is another whitelist test
END

my ($old, $new, $reset) = map "\e[${_}m", 91, 92, 0;
my %patterns;
push @{ $patterns{ lc $_->[0] } }, $_->[2] for @{ csv( in => \$csv ) }
+;
my $match = qr/(@{[ join '|', nsort_by { -length } keys %patterns ]})/
+i;
#use Data::Dump 'dd'; dd \%patterns, $match;

#$target_file->edit_lines( sub # NOTE line at a time
# {
# s/$match/$old$&$reset/g ? print "\n" : return;
# 1 while s/\Q$old\E$match\Q$reset\E/ print; ask( $1 ) /e;
# print "$new$_$reset";
# } );

my $pos = 0;         # NOTE replaces whole file for each change
my $more = 1;
while( $more )
  {
  $target_file->edit( sub
    {
    pos($_) = $pos;
    if( /$match/g )
      {
      my ( $was, $where, $pre, $post ) = ( $1, $-[1], $`, $');
      print "\n", $pre =~ s/^.*\n(?=.*\n)//sr, "$old$was$reset",
        $post =~ s/\n.*?\n\K.*//sr, "\n";
      my $replace = ask( $was );
      $was eq $replace or substr $_, $where, length $was, $replace;
      $pos = $where + length $replace;
      }
    else { $more = 0 }
    } );
# print "\e[33m", $target_file->slurp, "\e[0m"; # FIXME here for testi
+ng
  }

print "\nresult:\n\n", $target_file->slurp; # FIXME here for testing

sub ask
  {
  my ($was) = @_;
  my @choices = uniq @{ $patterns{ lc $was } };
  local $| = 1;
  if( @choices > 1 )
    {
    my $n = 1;
    printf "%8d. $new%s$reset\n", $n++, $_ for @choices;
    print "     replace '$old$was$reset' with ${new}above pick$reset (
+or 0 to not change) : ";
    my $pick = <STDIN> =~ tr/0-9//cdr || 0;
    0 <= $pick <= @choices or $pick = 0;
    return ($was, @choices)[$pick];
    }
  else
    {
    print "     replace '$old$was$reset' with '$new@choices$reset' ? y
+es/no : ";
    return <STDIN> =~ /y/i ? $choices[0] : $was;
    }
  }
[download]

Sample run (in glorious color which of course is not seen here)

a. this is some whitelist test
b. for IP whitelist testing and your whitelist

       1. allow
       2. access list
       3. access-list
     replace 'whitelist' with above pick (or 0 to not change) : 

a. this is some whitelist test
b. for IP whitelist testing and your whitelist
c. line with no replacement

     replace 'IP whitelist' with 'IP access list' ? yes/no : 

a. this is some whitelist test
b. for IP whitelist testing and your whitelist
c. line with no replacement

       1. your access list
       2. my permission list
       3. thy permission list
       4. his permission list
       5. her permission list
       6. its permission list
       7. our permission list
       8. your permission list
       9. their permission list
     replace 'your whitelist' with above pick (or 0 to not change) : 

c. line with no replacement
d. with whitelist and IP whitelist entries and IP whitelist entries ag
+ain.
e. this is another whitelist test

       1. allow
       2. access list
       3. access-list
     replace 'whitelist' with above pick (or 0 to not change) : 

c. line with no replacement
d. with whitelist and IP whitelist entries and IP whitelist entries ag
+ain.
e. this is another whitelist test

     replace 'IP whitelist entries' with 'IP access list entries' ? ye
+s/no : 

c. line with no replacement
d. with whitelist and IP whitelist entries and IP whitelist entries ag
+ain.
e. this is another whitelist test

     replace 'IP whitelist entries' with 'IP access list entries' ? ye
+s/no : 

d. with whitelist and IP whitelist entries and IP whitelist entries ag
+ain.
e. this is another whitelist test

       1. allow
       2. access list
       3. access-list
     replace 'whitelist' with above pick (or 0 to not change) : 

result:

a. this is some whitelist test
b. for IP whitelist testing and your whitelist
c. line with no replacement
d. with whitelist and IP whitelist entries and IP whitelist entries ag
+ain.
e. this is another whitelist test
[download]

The above output is in color, using red for the existing string and green for new ones.
This should be run in a terminal that takes ANSI color codes.

Is this the kind of thing you are looking for, or have I gone overboard ?