autovivification has lexical scope, so if other modules rely on autovivification, then using no autovivification in your script/module shouldn't harm them. (The only exception I could think of would be modules that play with B::Hooks::Parser, etc, to do weird stuff within your lexical scope.)

I don't see much value in explicitly specifying the 'exists' option for the autovivification pragma, as the default options are pretty sane: when no autovivification is in effect, autovivification will still be allowed for "store" operations...

use strict;
use warnings;
no autovivification;  # default options

use Data::Dumper;

my $ref = undef;
$ref->{foo}[0]{bar}[0] = 42;  # store
print Dumper $ref;
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