Ha ha ha, great post. Great to see all the greens prepared side by side, I'd love to be there for a tasting. You could create a single score for bitterness appreciation, mark each question on a scale of one to five then present the average... I'd totally end up with the top score! Munching on pure cacau nibs, with the most intense of mocha prepared coffees in one hand and a dark English bitter in the other, he he he. Maybe could add a common bitter vegetable to the list, like, hmmm, actually, that's hard to think of a very bitter vegetable that everybody would know, kale?? 

A trick I've picked up along the way through hanging out with foragers is to make a mix of various different greens, especially when making a salad. Like just bunch up a selection of wild greens and chop them into a bowl. That way no one single flavour dominates and it's a medley of bitter spectrums. Nyum nyum.

I'd like to share with you Macka B's rasta rap about bitter..."Don't run from bitter!":

https://youtu.be/SfHT4l7Fk_k