Issue transferred from the Google Group, screenshot from Ernir.
For me personally, I don't care if I can see the whole "keyword" in "my stories" (as most of it is usually just examples of vocab/readings (In reviewing and studying I like that I can see them though)), so a cutoff would be fine (maybe with an option to click it to see the whole keyword?). Or if it extends to two-three lines without overlap of the star, like you describe, whichever is simpler to implement :)
edit: to clarify; in the screenshot above, that would mean that I only need to see "isolate", and not the example readings. I guess the longest keywords would then be around 20 (ローマ字) characters (example: "j nightingale [nrm]").
Fixed by today's update (live).