I don't know, guys...

I seem to remember this being quite normal at the Seminary back at the turn of the Millennium. The priest set up the monstrance with the Blessed Sacrament towards the end (usually of a High Mass, on a big feast, especially those associated with a procession afterwards).

There is even a rubric associated with this. It is called "coram Sacratissimi" or "before [the face of] the Most Holy". Certain things are done differently coram Sacratissimi.

Agreed.  This practice is no novelty.  Our independent Traditional priest (ordained in the 1950s) had the same practice for many years.  Once a month the Mass flows this way into Benediction.  It's not an interruption of the Mass but a graceful transition.  Mass flowed into Benediction as Communion flowed into Adoration.

I think Matthew was just being polite.

In any case, someone else demonstrated earlier that, even if this practice of exposing our Lord in the monstrance while saying Mass is not the custom at my chapel, nevertheless, there is, apparently, a rubric in the 1962 missal (and earlier missals, per the St. Gertrude practice) permitting it, so I was wrong to have accused the practice of being a modernist innovation, and conceded the point.