You could probably do worse than to build your own extension that just wraps readability.js - the API isn't complicated, it just takes a document object and giv

You could probably do worse than to build your own extension that just wraps readability.js - the API isn't complicated, it just takes a document object and gives back an element tree you can use to replace the page body content. That'd let you control when and how it gets used, and also tune the heuristics to taste, neither of which is really available even to extensions with the browser's built-in reader mode. It feels pretty gross to duplicate native functionality, sure. But it probably beats waiting for browsers to start exposing those APIs; they don't do that for a reason, and that reason seems unlikely to change very soon.