That's true, but there is often more than one way to skin a cat. Redundant buoyancy? In some cases, there's no wing to fail! (Perhaps you consider that an egregious choice already.) In other cases, just a larger breath solves that problem. In this case, the OP is in a 7mm wetsuit above 50 ft, which is a buoyancy loss of less than 4.6 lbs due to wetsuit compression when properly weighted. They've stated agility is a priority and are using a small cylinder, so less than 5 lbs weight of air, yielding a combined total of under 10 lbs of negative buoyancy. This is easily swimmable and largely compensated (entirely by some people) by breath alone.But you gear list goes against literally everything I was taught in Solo diver
Without question the SDI solo recommendations are solid choices. I also think it's worthwhile examining the motivations behind them, as there may be other valid choices -- some of which have been expressed here by folks who seem to have the expertise to execute. (Don't forget this discussion is in the Advanced Diving section.)