Almost Perfect Rated 4 out of 5 stars

Very useful extension to get rid of those stupid icons on the tab bar (something Lightning should offer by in its preferences IMHO); however, there is one tiny bug. When you add these buttons now to the mail toolbar, they work without any issues, however, on my Mac, they don't get "highlighted" when you click them (usually, when you click a toolbar button and keep the mouse pressed, it is darkened until you release the button again; this works with all items except those provided by this extension).

This review is for a previous version of the add-on (1.5.2). 

I don't have nor use any mac computers, so I - of course - can't reproduce the issue. The issue might be related to the way the buttons should behave: they have a checked state, so the buttons stay pressed until you leave the calendar / click the button again to close the calendar. This is needed to provide better feedback when not displaying the tabbar.
Do you have the issue with the convert to event / task buttons as well? If not, I could disable the checked state thing on mac computers.
Please contact me via eMail, as the rating feature is not made for soving bugs.