In the case of a simple windrower like a swather, where you're just cutting the crop and laying it down, it's pretty straightforward to reverse engineer or design a parallel system. In the case of a combine, where there's so much integration between what the head does and the rest of the machine, it really needs to be an integrated solution. Reverse engineering that would be an absolute nightmare and, to be honest, beyond economic viability.
On February 25th, 2020. See this statement in context.