I don't have the kind of time it takes to read this entire thread, so parts or all of what I have to say may be repeats. That's okay. This is an important discussion. Don't forget that we're still in the early stages of the existence of this sport and it takes a number of decades to work out the bugs, especially as equipment and players evolve.
There is a mess here that needs to be cleaned up if the sport is going to go forward with integrity. There are two major problems. (1) There is an ambiguous, subjective standard. The 30 c.m. area behind the marker is not measured and cannot be substantiated by either party. That has to change. (2) Competitors also have to referee each other in this sport for a great majority of the action on the course due to the limits of funding. I'm not sure that can change for many years yet, so we have to do the best job we can refereeing each other.
Let's address point #1 because that's the easiest. First off, I agree that the rule is necessary, even if it was written before there were many holes long enough for good players to have to wind up with a full subsequent drive after teeing off. I think that pros especially should be held to a standard where they conform with planting their foot in a specific space in the act of doing what they're paid to do better than almost everyone else on the planet. Maybe the 30 c.m. distance itself is debatable, but once one is determined, every throw should conform with it for the sake of objectivity.
Secondly, now that the importance of that objective measure is understood, it must be objectively measured. Period. There has to be some sort of way to mark off the parameters that the player must perform. I've had a couple of days to think about it, and so far the best I can do is an idea with strings attached: a mini with a built-in 30 c.m. string...or better yet, a triangle made of three outer strings and the inner string (perpendicular to the base of the triangle) that shows the line with the basket. A player's supporting foot either makes contact with the single string (or triangular area) or doesn't. It becomes objective.
The messier factor in play here, however, is the fact that competitors with obvious conflicts of interest have to also referee each other in a great majority of the action in the field. Maybe this isn't an issue 100 years from now, but for the time being, there might be enough resources in our game to place a small handful of highly skilled 3rd party referees on a card just at very important events. That's not exactly a perfect fix, though, because of the dynamics created in cards close to the top who don't have referees. In the meantime, the "spirit of sportsmanship" is all we have. It probably is good enough 99% of the time or more, but when you have competitors refereeing each other, the potential is there for abuse (intentional or not...I can certainly understand the difficulty of this situation from both parties when you're talking about competitive human beings). It happened in a high-profile circumstance, and to be honest, I'm glad we're having the discussion now. It's a needed discussion in the evolution of our sport.
Without sufficient resources to position highly skilled 3rd party officials everywhere they are needed, this "spirit of sportsmanship" idea has to be trumpeted and understood by all. And that's certainly not easy to accomplish 100%
We're 40 years into our sport. That's it. It's like baseball in the 1890s. It's okay to have these discussions and modify the rules of the game where needed.