I decided against a topic other participants wouldn’t be familiar with — I decided it’s too hard to judge whether a map is any good if the topic is new to you.
I actually had an interesting experience as I showed the map to my partner; the topic he was familiar with he appreciated, but the unfamiliar one I think he just saw as a confronting mass of information. If the information is really new rather than a review, the non-linearity of the map means a novice doesn’t even know where to start in traversing the information, and (I think) it’s actually more confronting than a list.
So this is a pretty simple topic, python dicts!