This is just my opinion but . . .
I suspect Pd is the active material in these experiments, and it always has
been. Both Pd and Ni were sputtered all over the place in the old reactor,
with glow discharge. It has a large display of plasma, which I suppose is
sputtering metal all around.
With the latest technique described in Appendix A, the Pd is deliberately
rubbed or plated on to the Ni mesh.
I still wonder if Ni cold fusion even exists. The claims for it seem to
gradually vanish like a Cheshire cat. In my opinion, the most convincing
ones are Kitamura et al. and I do not find them all that convincing. Here
is the most recent one: