OK I played with this some more, it's so good - exactly what I dreamed of!!

A couple more bits of feedback:

(1) The "suggestion" / "I'm unsure" etc. feedback is fantastic

(2) Word segmentation doesn't seem to be working properly, and so the context lookup doesn't work right. Example:

中国 should be parsed as a single word ("china"), but it's parsed as individual characters ("middle", "kingdom").

This means I have to tab out to a dictionary to look up words, and it's a bit annoying to select the right text.