I like low starting angles on Gyuto's,then raise the spine & blend in a second higher bevel,when you do this you can hear the final bevel being cut in on the stone.A steady consistant spine is more important then % of angle.
On my work knives never used a Damascus blade.Start wt. shallow bevel close to the stone,then kick in final bevel.Did not care what the sides of the blade looked like as long as it was sharp & cut well.
These days sharpen Shuns alot for other people.Still start wt. shallow angle,don't let hardly any mud build up on the stone(rinse it off)Inspect your edge,even at the shallow angle should not hit the damascus line,just a little polish above the edge.It is a good idea to establish a higher final bevel as well on the Shun,it is still very sharp,good cutting edge & not as fragile.