The cruise terminals in Venice proper are now no longer in use to large ships, and the ships no longer can cruise along the canal between Lido and Venice proper.
So, you can forget about cruising to/from Venice, embarking/disembarking in Venice, enjoying the sail away from/in to Venice like the days up to covid. The ships now can only go to port somewhere in Marghera via the Santa Maria del Mare canal/pass.
Venice port has changed.
As for the ship's excursions to Venice, think hard before submitting yourself to one, your ship will port in Marghera and the tenders are long and you'll have little time in Venice proper. Not worth the time and expense. Best to do a few days in Venice proper (there'll be less people, no doubt) pre- or post-cruise and travel to/from Trieste on embarkation/disembarkation days.
P.S. I have heard Trieste itself is very nice place to stay a day or two pre- or post-cruise.