Thanks for the suggestions! Most of the flight will be ACV ticket holders. I looked to pay cash for the ticket but AC was only selling Latitude and J and it made little financial sense to not book through ACV. I was offered J through ACV for $500 more per pax return but decided against it. Regretting that decision a little but I ultimately decided it wasn't worth the money on an A320.

Will use the eupgrades and hope it works in my favour since only SEs and E75s can use eupgrades on ACV bookings.

FYI - currently the return is not bookable through ACV even so it looks like it is in fact Y0.