From the source of the package - leading zeroes are stripped.
In the 'private' (_split) method:

sub _split {
   ...
   $x =~ s/^\s*([-]?)0*([0-9])/$1$2/g
   ...
}
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So you may want to re-write the substitution to:

   ...
   $x =~ s/^\s*([-]?)(0*[0-9])/$1$2/g
   ...
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If this is acceptable at all.