Thanks for building and sharing!

I generally like this as a learning tool, but some of the situations could use more setup to guide the learner towards the specific rule being tested.

For example, I got this one wrong because it was not clear to me the question assumes yellow did not have time to change course / if blue does not change course they will collide. If "The move" had said "You hold your course, causing contact with yellow", that would have been a stronger setup, as it is impossible to infer if there is/is not still plenty of time for Yellow to change course using just the drawing.

Same thing happened in the section when it came to luffing rights. This situation's answer (and another before it) turns on how the overlap was established, but the setup does not tell you how the overlap was established.

This is as far as I've made it, but I'll definitely keep an eye on this. I've found rules-related questions put to AI to be answered ok for the basics, but replies are quite poor for tricky situations involving multiple rules. So Im curious if you verified all the situations/answers throughout the tool.

Clearly placed there by a trimmer trying to share the guilt! ;0))

Agreed - it's important to note that not all GPS tracking technology is equal so not sure how you would handle that.  Yellowbrick sends data once every 5 minutes and I have had protests over it showing a boat not rounding a mark when in fact they according to the boats that were there too.  Just caution at this point with the tech.

Thanks very much John. I appreciate your efforts in replying in so much detail.

Our annual program includes a Pointscore Series (Pursuit format; scratch -> biased towards slower boats) run every fortnight ( 15 races per season), Championship (Yardsticks; 2 races each day; 14 per season) and Sprints (Yardstick, 3-5 races per day; 24 say races per season) => run in turn every other week.  (so C-P-S-P each month).
 
We'll be running our annual October Regatta (6 Divisions) , Hobie States, Spiral Nationals + the International Canoe World Titles this year so we'll be busy, and having lots of fun and enjoyable times out on the Bay!

As Race Secretary I want to apply a common entrant list and a common set of rules for our club races. (KISS).  We are transitioning from a Cox-Sprague system to low-point (Sailres) next season. We have a meeting next week to decide on the rules.

After much research and simulations and yours, and others kind feedback, my preferred approach is DNC= Starters+4. I thinks the committee could settle on DNC = [12] which is starters + 4 for our average fleet size of 8-10. There is a group who want to keep the regatta approach of Entrants + 1.
 
We'll see who 'wins' the debate. Interesting Times (pun intended)! 

Cheers and Thanks again for all the great feedback. 
PS many clubs face similar issues and so it is worth discussing it here.

Looks like several scoring systems allow for it.  You will find the instructions for how to do it on RacingRulesOfSailing.org here.