Hi, we tried the RYGGED start at our club, but found the less experienced skippers found it hard to get through the fleet to the line at their appointed start time.
We now just set 2 windward marks, one several meters shorter than the other for the handicapped skippers to sail around. This has the advantage allowing us to lenghten or shorten the handicapped course depending on the conditions.
Overall though, we have found it difficult to come up with a handicap system thats works well & certainly haven't found one that works well from just using maths. Best to try several methods & see what works best for your fleet, venue & conditions.