Well I do have spacebucket experience, but also not one to say much when people are having fun building…
I’ll share in my experience with bucket growing and things that worked for me.
Side lighting for me was a waste for the most part and really only the top 1/3rd is where having light was best for me as once plants grew into the light they blocked anything behind them, even though your thinking center column light for growing you would probably only want top 2/3rds, and strips would be good for that.
Fan wise exhaust was only needed for me, I did side intakes that swirled the air coming in, and that work really well.
Pot size I over estimated, and likewise say your 4
1 gal pots, with automated watering I bet only one would be needed, but 2 or three will speed things up for sure.
So big issue I had with bucket growing was when pruning was needed it has hard to access what was needed so consider how your gonna get to the back or front side of your cylinder, your probably gonna have to lift it out periodically.
Also the 26sqft in 4sqft footprint is partially flawed not that vertical growing doesn’t add surface area it’s just cause as the plants grow inward that sqft is reduced especially when leaves and buds block those behind them.