The Custer Channel Wing has been modeled at least twice in the past. From what little information is out there the models were unique but unremarkable as was the full scale airplane.
The real airplane was a vibrating underperforming dog. It had a lot of aspects that suggested that intuition rather than aero engineering went into the design. The airframe as I recall was a worked over Bauman Brigadier.
The photo that you have displayed is showing the airplane climbing out of the ground effect rather than any true vertical component to the climb.
Later studies showed that the performance would have been marginally better if the props had blown the accelerated air over the wing channels. Although the channel configuration has a very small vertical lift component and mostly drag associated with it.
All that aside, as a model where the power to weight ratio is high and the strength to weight ratio is very high, it would make a model that no one would ever confuse with a run of the mill light twin. In fact you could probably get the kind of performance out of it that was envisioned for the real one.