Hi @atewesk,
I do not have the exact number (I will try to find some number in the next days) however the spectral responses of the S2A and S2B satellites have some differences as you can see in the graph below and the previous model was tuned only on the S2A sensors (the S2B data were not yet available when the previous version of the algorithm has been developed).
I will let you know more details about the improvement in the next days.
Cheers,
Martino