The challenge with the split/recombine methods on these wide emitter diodes is that you have to split the fast axis, which is a thin beam in the near field (not the widest of the 2 axes). This expands quickly in the far field to become the wider dimension. I'm not sure whether telescoping the fast axis up in size first to do the split and then telescope it down after recombine would help? That sounds tricky and expensive in optics and mechanics though.