With beta 10.51 and custom watch face working as before 9.20 and ~0.3% per hour consumption w/o any activity. Beta installed on 05 Aug 20:20 h, full battery charge and after 14 h 30 min with 2 hours and 14 min walk with GPS 82.12%. Still evaluating, but I think Garmin resolved the battery draining issue w/o any comments on that ;).