In many cases, including this one, spaces will kill a formula. Looking at the face right now, this is what you have with spaces: $#DOW#=0?30:0$ $#DOW#=1?-30:0$ $#DOW#=2?-20:0$ $#DOW#=3?-10:0$ $#DOW#=4?0:0$ $#DOW#=5?10:0$ $#DOW#=6?20:0$ - - so if you use $#DOW#=0?30:0$$#DOW#=1?-30:0$$#DOW#=2?-20:0$$#DOW#=3?-10:0$$#DOW#=4?0:0$$#DOW#=5?10:0$$#DOW#=6?20:0$ instead without spaces, it will work.

Another option: if you rearrange the days on that scale to start with Sunday, so that you have Sun-Mon-Tue-Wed-Thu-Fri-Sat instead, you can make the formula tremendously simpler: ((#DOW#*10)-30)

In general according documentation, $ is used to start and end of the conditional expression. If the brackets in their place work too, its probably not intentionally so.
Also check and try to use == instead just =. Some watches may have trouble with just single sign.

With my remark about why not 0 for Monday, I meant: i dont’t understand why the makers of Facer don’t start the week with a Monday.
My calendar week and working week starts Monday, not Sunday

In many countries they go by old testament week days and relate the Saturday to the seventh day - Sabbath and do not follow the international standard. Facer resides in one of them.
If you want to start the week at monday, then you can slightly modify the rotation formula like this: (330+10*((#DOW#+6)%7))