My expectation is that if this technology was widely deployed in the Sahara, any afforestation attempts would be cut short because they step on the toes of the vertical farming guys.
Not only will individuals loose the ability to farm, it will be locked up in companies. Who will likely make it illegal for others to do the same.
Beyond that we will likely loose access to all strains of plants that’s can grow well outside.
As a safe guard. Humanity needs a super farm that is isolated and trains and maintains the old ways.
First you still need water, and its not like its a closed system, so you'll get significant losses.
Then you need to either think about heating and cooling (it gets really cold at night and super hot in the day) or build under the sand. Either way lots of building materials.
Its literally easier and cheaper to terraform the saraha than it is to do vertical farming there.