I'd appreciate the ability to use calculated metrics with histograms.
Would also like this ability. I am quite sure that currently the histogram isn't much used. Let's hope Adobe analyses & optimizes their functionalities 🙂 Adding the possibility to drag calculated metrics into histograms would definitely increase relevancy of this functionality.
Archiving as a duplicate of Use Calculated metrics inside segments because that is the root of the reason why calc metrics are unsupported in histograms.