OK + Feature suggest. Rated 5 out of 5 stars

It Works! I can't beleave it. A highlighter that works.

Some suggestions:
A• the "A" icon i think that should have the same heigth than others. (to maintein some harmony, imho)
B• the search and clear icons have a white background and they realy don't looks very fine in dark Personas (or themes). I think that they should have a transparent background (like undo).
C• Also to improve icon's readability (make them more distinguishable, at least for dark theming UI configurations) you could change the clear, find and undo icon for a dark gliph style icon for defaut or whiteness themes, with an option to change these icons to a darkness set for dark themes or Personas.

This review is for a previous version of the add-on (initial.rev802.1-signed).