It seems to me that spin is important in LENR because spin somehow correlates with mass. The key to the LENR reaction is the production of additional mass of the quarks that comprise hadrons. This change in quark mass is induced by unbalanced magnetic field lines. This type of anisometric field lines produces an increase in the spin rate of the quark which will add energy to the quark. Balanced magnetic field lines do not increase the spin of the quark. When the quantum of additional spin energy is reached, the quark will convert that spin energy into additional mass. When mass is added to a quark, the flavor of the quark changes and the quark will jump to the next higher flavor. For protons and neutrons in an anisotropic magnetic field, the up or down quark will transform into a strange quark, the flavor that is the next up in energy/mass size. This change in quark flavor will convert a proton to other subatomic particles that end up as kaons.
Actually, things get more complicated. The lambda is a baryon <http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/baryon.html#c1> which is made up of three quarks: an up, a down and a strange quark. Based on the amount of magnetic energy that is pumped into the proton or the neutron, however, a variety of different Lamba particles can be produced. The third converted quark might be strange, charm, beauty, bottom, or top. This Lambda particle will decay in short order to produce a zoo of different decay particle types including the kaon. And then thing get even more complicated when subatomic molecules form. http://physicsworld.com/cws/article/news/2015/apr/07/mysterious-baryon-resonance-is-a-subatomic-molecule-say-physicists