The best starting point would be to make new timing marks 17 teeth counter-clockwise on the camwheels from the original standard marks.Make sure you can distinguish them from the standard marks.
Use the keyways closest to the new marks.That will advance both cams 4.8 crankshaft degrees,when you time it to the new mark.Chances are that will be as good as it gets.
Norman Hyde advertises these cams as "full-race",and his suggested timing is measured as valve lift at TDC.
INTAKE valve gross lift :0.195"-0.210" (approx 0.180" tappet lift)
EXHAUST valve gross lift :0.175"-0.190" (approx 0.162" tappet lift)
If anything,you could advance the exhaust slightly on a touring bike,to get better response at non-race speeds.One full tooth error will change the TDC tappet lift approx 0.050".You can adjust it in 1/3 tooth increments,using different keyways and new timing marks.