You could make a copy of AoA1 with them grepped out.

my @cleaned_AoA1 = map { grep length, @$_ } @AoA1;
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If you don't mind being destructive, you could remove the blank elements from @AoA1.

foreach (@AoA1) {
   @$_ = grep length, @$_;
}
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I'm afraid that's the best NestedLoops can do because it can't loop using iterators.

Grepping them out on the fly won't save you any memory.

sub make_scrubber {
   my ($aref) = @_;
   return sub { [ grep length, @$aref ] };
}

my $iter = NestedLoops(
   [ map { make_scrubber($_) } @AoA1 ]
);
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