It was found that the method developed by "A" (newer designers) versus "B" (the original designers and holders of a patent) was more complex. I think it falls into the improvement patents category, in the same application domain and with the same scope and goals. Nothing is new here.
But "A" has a bit more complex of using the procedure B, which is entirely patented by "B". Using, it means "black box", nothing is changed, the idea is the same. But the method created by "A" also has procedure A which is not included in the patent held by "B". So it is like "A" is using the patented procedure B in certain cases and, depending on the inputs into the system, switches to the procedure A.
I understand that USPTO might reject the approval of patent from "A" based on not too much novelty compared to "B" and being for more than 2 years away from approval of "B".
But, is this also a situation in which "A" is actually infringing the patent "B"? And this would require a licensing of "B"?