I get what you are saying completely on the logistic/risk parts.
The light penetration thing, although a good point I still disagree with. You may get deeper penetration (straight face) if in a 3x3 under normal grow conditions but the density of buds the lower you get suffers, this is why the likes of UB topping for 4 is out dated if pushing for weight. If you spread out that canopy over a cage it is obviously less dense but the area will increase a lot more. The most important part is the light hitting most of the thin canopy at optimal intensity. Essentially every bud is going to have the density of top bud and although smaller in size, they will out weigh donkey dicks volume wise.
In an ideal situation you would first max out surface area canopy. With that maxed out you would also max out light intensity/spread to cover that area. Once that's maxed out you would have no other real option but to increase canopy density where possible, but that could detract from initial surface area.