If anyone is interested here is my 2*2 Deep-Field pad, that has the size of the regular 2x2 pad, but combines 4 regular coil-pairs in stacked configuration:
Together with B5:
I think it is more potent then the regular pad - at least for localized issues at my back.
And a 2*8 pad to wear as a belt under the provided strech-belt oder along the spine.