Has anyone cycled along the south shore of Walensee (Lake Walen)? Is it necessary to take the high road between Murg and Mollis, marked as "Kerenzerberg Pass" on one of my maps, or is there a route that stays at lake level for cyclists that avoids the 300+ metres of climbing?

There is an indication of a lake-level route on the Kumerly-Frey 1:301,000 Swiss cycling map, and there is a track marked on Google maps that seems to correspond. However, my topographical 1:100,000 SwissTopo map doesn't have anything marked that suggests that there is anything rideable along that section of lakeshore. Maybe someone more local can give me some reliable information about the condition of the road/track along the southwest section of the lake.

Normally I would enjoy the extra 300m of climbing, but I may use this passage as part of an epic-distance ride in which I'd like to avoid any unnecessary pieces of climbing.