I bought VT2 vents for a Nitro but sold the boat before installing them. I planned to install them on the replacement boat, a 2010 Pantera II. I never did because the livewells were so much better!!! I have had over 70 pounds of Hybrid Stripers in it on a hot summer day and they were a serious PITA to get out. Same with bass too but never that much weight in there. I have never lost a fish that wasn’t gut hooked and even most of them recovered. I set recirc on 5 and aerator on 3 and just fish. There is no need for anything additional with a BCB Advantage or Premium boat. The new P Classic has basically the same livewell system my Nitro had. I might consider the vents for one of those.
Do the VT2 vents work? Folks who have them believe in them. I personally have fished as a coangler on several mid-90s boats with them installed and the fish do better than they did in my Nitro. They were very lively. I think the vents help just getting the hot air out of the well. That alone has got to be good for the fish!
If I were in your shoes, I would not install any oxygen system in a BCB. I would install the vents if I was switching from the lid latches to side latches for the livewells or if I just needed confidence in the livewells. I can tell you though you do not need anything if your livewells are clean and operating properly.