Multistrange Ca, Sn, and Pb hypernuclei with $\Lambda \Lambda$ pairing interaction are investigated within the Hartree-Fock-Bogoliubov approach. The unknown $\Lambda \Lambda$ pairing strength is calibrated to match with the maximal value for the prediction of the $\Lambda$ pairing gap in uniform matter for densities and isospin asymmetries equivalent to those existing in multi-$\Lambda$ hypernuclei. In this way, we provide an upper bound for the prediction of the $\Lambda$ pairing gap and its effects in hypernuclei. The condensation energy is predicted to be about 3 MeV as a maximum value, yielding small corrections on density distributions and shell structure. In addition, conditions on both Fermi energies and orbital angular momenta are expected to quench the nucleon-$\Lambda$ pairing for most of hypernuclei.