I would skip the O air if you want BIZ class
The Air is not "FREE" you got a discount when you booked cruise only
Check the price of SM with air & without
Contact your TA or Oceania who ever you booked with & see if it is worth it to you to go with SM program or not
Try this
Do you have the OLife House select package ?
If so then if you want to upgrade to the Prestige it will be $40.33 CAD or $30 USD pd
If you do not have the House select package and you want the Prestige package it is $94 CAD per day
All are PP rates
Make sure you know what terminal the ship will dock at
Some are further away than the one you posted in your link
https://www.portquebec.ca/en/cruises/information-for-cruise-ship-passengers/access-to-docks
https://www.portquebec.ca/en/cruises/vessel-schedules/seasonal-schedule
Not ORV but
it may be busy in the afternoon but there is no shade on Marina/Riviera so depends on how many people like to bake to death
it is Concierge & up that have access