At least rule 18 got better after patch 1.3, but way to go...
The most annoying thing is that boats entitled to room receives pens from other rules during the rounding (typically rule 11). Duran: Simply turn off the other rules when a boat is entitled to room and is manouvering inside a defined zone around the obstruction...
Rule 18 itself shouldn't be hard to code, as it's only a matter of geometry... Who is overlapping who when a boat is entering the zone!
Harald