This may not help with that particular watch face, but I noticed that there is an option in Watchmaker that will allow you to turn off "indicators". I haven't tried it yet, but maybe this will remove the star icon for you. Of course, you'd have to be using a watchmaker watch face for it to work.
To try this out, download watchmaker
HERE, pick a watch face and select "customize watch". Scroll down to "indicators" and tap the "x" to the left (screenshot below).
Also, if this works and you plan to use watchmaker for a while, I'd recommend springing for the premium version. Well worth it IMO!