However, we need to realize that Benediction and Adoration are entirely different from receiving Our Lord in Holy Communion. There is a reason why the priest wears a humeral veil. It is to show respect and reverence for the Blessed Sacrament.
According to Redemptionis Sacramentum:
[137.] Exposition of the Most Holy Eucharist must always be carried out in accordance with the prescriptions of the liturgical books.235
Note that the key phrase here is “with the prescriptions of the liturgical books”. To my knowledge, there is nothing in the liturgical books that indicates that the faithful should be touching the monstrance, let alone, the luna where the Blessed Sacrament is housed.
Look at the Monstrance as though it were the Ark of the Covenant. The Ark prefigured it and the Tabernacle, so to speak. Remember the prescriptions in the Mosaic law that prohibited anyone from touching the Ark. The only time that a lay person could conceivably be touching the Monstrance is if, for a compelling reason, he would have to repose the Blessed Sacrament back into the Tabernacle. But, even then, the only ones who should even be handling the Monstrance are either the deacon, priest and bishop.