Cross-validation of a cross-validated stacking ensemble?
I posted this same question on Reddit and someone was kind enough to answer

By https://www.reddit.com/user/patrickSwayzeNU


  This
  
  
    When I do CV B, is it valid to do CV A just once and use those out of fold predictions for the entire CV B process?
    
    Normally, I'd think that there'd be some data leakage in the first method, but one could also reason out that since the out of fold predictions are taken, well, out of fold, that issue is taken care of.
  
  
  Yes, your data set created by CV A is now "good as new".