Avoiding A Gem For 12th From Ra/Ke's Placement

Hi Ernst,

When using the rule of avoiding gems that correspond to a graha's placement in a dusthana from it's natal rashi position, how does that apply to Ra/Ke's position with regard to the 12th house, since they move in reverse?

Should we treat the 2nd house from a node as the 12th in this case?

Thanks,

S.