I've never been taken by the stud-rail idea. It seems like a lot of changes for what will still be a "compromised" appearance, and the sliders...well, no thanks, really.
If a 3-rail stud (t-shirt idea, there) system were started with a clean sheet of paper, and I mean the locos, too...but a conversion? Unseen issues. Cascading anomalies. Less than stellar results and appearance.
I certainly wouldn't be a user - too much to change and modify. Guys with small inventories, perhaps.
Likewise I will stick to the large O-gauge couplers, at this point. On scale equipment they look less large, and I certainly can't convert my "fleet" - locos (small electros) or rolling stock (to Kadees).
2-railers: an opportunity missed, 30 years ago. Too inflexible. Sad.