Although unasked:
My best guess is that the functionality provided by https://polymer.github.io/lit-html/ was meant (mistakenly attributing the feature to the micro framework).
Thanks for pointing this out to me. I hadn't heard of lit-html before. Another case of learning about something very useful via HN :) Yes it is lit-html that I was impressed by more so than the micro framework that uses it. When I say automatic differentiation I mean treating different binding types (text value vs event handler) differently.