In some classes it makes perfect sense. Optimists in Ireland and UK use a season- long set of SIs (Major Event SIs) which have been beaten, prodded, tested, corrected and hammered into a robust form by a number of IROs/NROs/IJs/NJs used to cover regional, national and other fleet events at club level. Occasionally, items arise at a specific venue or point in the season where amending these within event-specific Supplementary SIs is helpful, rather than posting "big" amendments to the MESIs. 

Same applies to NOR, particularly where these may be drafted and issued months in advance (even the prior year) for e.g.  National Champs, major events such as Cowes/Cork/DL. 

Fully agree this needs to be managed carefully and the earlier the actual Race officials can help with review the better, and stay away from the "contract" elements for sure!!

Ultimately - I always prefer drafting/reviewing  both together, even if the SIs then sit in a drawer until the event. 

Yes that is my understanding.

Interestingly, I have just researched MLS Rules - The mid-90's American modified 'soccer' rules.  It didn't really work.

However, MLS did have a countdown timer as Ang describes as well as some other variations to the traditional game.  MLS Penalties were pretty funky.

The MLS rules lasted 4 years.

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In this research, I find that the football rule makers, IFAB, remains institutionally conservative and deliberately resistant to game changes.
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I'm also finding that what I see as poor sportsmanship is, in some places, seen as the art of being street-smart and 'doing whatever it takes to win for your team'.  Perhaps all those dives and feigned injuries I saw Columbia doing the other night were heroic... to Columbians.  Tactics celebrated as "viveza" or "gamesmanship".

If half the footballing world are happy with that, things will never change.

On-field tactics such as shirt-pulling, heckling the ref, appealing when knowingly last touched, diving and feigning injury will always be worth-a-go.  If you can't beat them, join them.  Off the field, the unseen underworld will continue to prop up the sport, rightly or wrongly.

I don't think there is a solution coming any time soon.

Yes John, as I said there were obvious limitations with the selected model (not ideal of course but reflective of the reality of funds availability) – albeit, implemented from the outset on an ‘eyes-wide-open’ basis by all the parties, as I understood. 

By ‘senior IJ online support’ if needed, I mean to simply call on an ad hoc basis - where second opinion felt needed to be sought – and to remotely follow things.

We have attempted to recruit more JITs here (just myself at present) to no real avail so far but are actively seeking same for the future seasons. 

Appendix T route was included in the SI’s, for those applicable matters (in fact, it was well engaged in the third regatta) - but is still a bit ‘novel’ for competitors here it would seem (I have also noticed that some IJs are supportive of Arbitration process and others are not).

The process of elevating any Appeals was fully understood by all (via MNA etc) – just that none were forthcoming.

That being said, it all seemed to go along quite well 'considering' – from the perspective of MNA, OA (budgets) and competitors etc. I am not sure yet if this model will be selected again or otherwise for the coming National Season4 or a more conventional approach adopted (TBC), and for myself, I will just fit-in again with what is selected by them.

Is there a reason a finishing window couldn’t be based on the first boats elapsed time plus x%.
I.e. 50% = first boat 60 minutes, last boat 90 minutes, or first boat 120 minutes, last boat 180 minutes. 
The % could be chosen based on the handicap spread of the division - tighter fleet, smaller %, wider fleet = bigger %. 
I think this would solve an issue for my club. We currently only have a time limit of 2 hours for 1st then 3 hours for last. Our winter series can be either cans or harbour courses. The 2-3 hours is really for the longer harbour courses. We’ve had short cans courses lately due to light winds. The first boat has taken 40 minutes, the rest of the fleet done by 50, but one boat who should be mid fleet is off the pace, and took 100 minutes. Wore a bit thin with the start boat, who then got back in the dark, which then delayed prize giving for everyone else, but didn’t break the time limit rule. However, a 30 minute window wouldn’t be big enough on a 2 hour race, but 1 hour is excessive on a 30 minute race (we had one race which only took 20-30 minutes) . Can it be flexible as suggested? Or must we resort to the complicated (for or RO’s) formula / app to calculate? I can’t see anything in the rules.