Here's a performance, for anyone not familiar with the Martin arrangement:

https://youtu.be/fEOLUnoQdmQ

The piece is too long for a recessional and too grandiose for communion. Maybe at offertory, IF there is lengthy ceremonial to be done (procession with gifts, incensation of the altar, the ministers, the people). It's almost five minutes long. Otherwise it could only be a prelude.

Apart from the functional question, it might or might not be a good fit, depending on the homily. A baccalaureate Mass is typically a Mass of Thanksgiving, while this song has a theme of scorning worldly things in favor of glorifying the redemption obtained by Christ. If the homily is giving the same message, then you could sing this at offertory if the time allows. And if the key changes -- I lost count after five -- don't come across as a cheap effect.

Maybe a more conventional arrangement would be a better choice. Well, considering that the congregation will include many infrequent Mass attenders, maybe it's no time for subtlety.

I didn't recognize it at first, but I do know the piece.

If your priest intends to preach on the cross the baccalaureate class must accept because the world hated Our Lord before it hated His faithful servants, I can see a place for this at Offertory. If he plans to tell them how much excitement there is in front of them as they begin to live their dreams, and that this is just the beginning of the adventure of their lives..... I could see cognitive dissonance setting in quickly. Maybe you should check with your priest.

At another level, this piece is a large-choir piece. Do you have large choir?

It's very nice, but it comes off as extremely Protestant and not really appropriate for Mass. That is, not only are the text and musical form very Protestant, this isn't even on the top ten list of pieces familiar to Catholics.

Sure, sure, motets and chant largely aren't, but hymns in English are for singing, and if it's unfamiliar or winds up being a concert piece like this, then people will just get frustrated. On the other hand, you don't have to sing long motets, and you either are open to chant or you are not, but everyone groks right away that the propers are not strictly speaking congregational pieces. And if they like Ave Maria, then they can ease their way into the other stuff by their own logic.

Unless it's a hymn familiar to the congregation, I would avoid using it as a hymn at such a Mass. While it's a hymn that appears in hymnals that are used in US Catholic churches (set either to HAMBURG or ROCKINGHAM - neither of which IMO is particularly wonderful for an anthem arrangement), in my experience I've never heard it sung at Mass in a Catholic church in over 50 years; I've thought it might be deployed for Stations of the Cross and Sacred Heart devotions.

If it had to be used, it would only be for Offertory, not Communion.

The arrangement in the recording, by Gilbert Martin, is based on HAMBURG. I was quite surprised to learn that this tune by Lowell Mason (1792-1872), known for encouraging the teaching of music in U.S. public schools, is itself based on a plainchant psalm tone! Dr. Mason, a Protestant, was in favor of using chant, though he preferred Anglican chant or chant rendered as hymn tunes, because he thought these were easier for congregations to sing. The full story on HAMBURG is in an article by David W. Music (yes, that's his name) in The Hymn: A Journal of Congregational Song, Winter 2017, Vol. 68 Issue 1, pages 24-30.

FWIW, I agree with others that this might not be the most ideal thing for a Bacclaureate Mass, though it might work for the Triumph of the Holy Cross.