Today I stumbled across a cool post on Reddit: Design your own watch face on a Galaxy Watch 4 with the following video on YouTube:
This evening, I downloaded the Samsung Watch Face studio.
This is what I got after just one hour:
Battery, time of next calendar event, date, unread notification count.
My always on display:
Just two hands and unread notification count. As few pixels as possible to save battery.
Excellent developer tools. Everything worked like a charm. Now I have to do some tweaking...
I tried out the new watch face today. At night, I used battery save mode. During the day, I used always on display (AOD), but I inactivated tilt to wake since the AOD showed me the time. To my big surprise, battery level at the end of my work day was 42 %, practically the same as when using the digital dashboard clockface without AOD.
I will tweak my clockface a little bit. The "unread notifications count" on the AOD is unnecessary as there is a red notification dot anyway. I will make the hours hand somewhat shorter so that the AOD becomes easier to read. As the inside of the bezel has markings in 5 min intervals no ticks on the clock face are needed. When everything works to my satisfaction, I will share the clockface via Google Play.