I see many videos of Serrada these days where people are doing things that Angel worked so hard to train me not to do, things like cocking a #1 strike back behind the shoulder, or reaching in with the check hand automatically in lock position at the end of techniques, or stepping into daga range on basic techniques. Those are details I try so hard to pass along to my students so that Angel's insights don't simply disappear. After all, he had reasons for ever inch of movement, and we went to train with Angel to gain his insights from real combative experience, so why would we ignore what he shared with us?
Most of those details should be familiar to direct students, certainly those from the 80's when Angel claimed to open up his teaching completely. There are of course some variations between practitioners, based on skill and application in the moment, but overall the folks who were training during my time with Angel are technically very similar to how I was taught.
Passing along a martial art is like the childhood game of telephone, where kids sit in a circle and pass along a message whispered from one to the next. By the time the message goes full circle, it is often completely scrambled from the original. This is common to many arts, and one reason why different lineages appear. It's one thing to innovate and explore, making the art one's own, but it's another to lose sight of the original intent and practices.
I'm by no means saying I'm the sole repository of Angel's knowledge. He taught many people, and some lessons may only have come from a specific question in a class or been shared with those whom he trusted. This is why there is benefit in training with a variety of instructors. That's one thing I really liked about Aikido training, that teachers would visit each others' schools and share their insights. An arm bar is an arm bar, but there are different ways to make it effective, after all. Still, Angel was as sharp and discerning a teacher as I've ever met, and it would be a pity if years from now the art bearing his name were to become something he would not recognize or acknowledge.