I asked Marop about the later years. The tables were always marked, as the rules require.
The Diamond wooden triangle is particularly bad as it is thick and has a pointy end, but it was used and the tables were marked with it.
I commentated on over dozen of these matches over several years. I looked on youtube for those matches, which were played on tables upstairs used for the regular tournament. I haven’t seen a triangle outline on those. I’ll assume I just couldn’t see the outline from the booth.
You keep saying there is no good reason to change this rule, so I’m surprised at the total dismissive attitude.
1. Balls that are non-interfering with the balls yet interfering with the rack can be playable if we use a ballmarker
2. Ballmarkers like today’s markers didn’t exist before in US Pool. Now there seem to be a dozen different great options.
3. Today’s Perma-Rack already has shown what could happen if we use a ballmarker, meaning at least Shane’s shot shows him using a break ball that would have been interfering with most if not all of today’s racks. This is the same shot as he had to get an out-of-play ball to see if the break ball interfered. Not with a rack but with a racked ball.
4. Ballmarkers are already incorporated in other games for various reasons
5. There isn’t only one monstrosity rack. They’ve now become the norm. The rack itself has evolved. Something like a ballmarker takes the rack and it’s growing size out of the equation. Predator rack is a great example.
6. If traditionalists must have an outline, outline just the balls and no gap behind behind the rack. If a 15th ball ends up interfering with the actual rack in the back, use a ballmarker
7. If traditionalists must have an outline of an actual rack, what outline? See #5. A suggestion is to have a standard rack closer to yesteryear. What happens if the venue or event only has racks bigger than the prescribed outline? A ball marker solves that issue.
That’s plenty of good reason. And when this was brought up in the straight pool forum, plenty of people like the idea, while (like one person) were pretty traditionalist about it.