You should check out Tristan Tucker’s TRTMethod. I think you’d get a lot of mileage out of it. He has some episodes on youtube that you can check out to get an idea of what its about. In particular he has 3 called the vertical mare and another called, I think, the tense gelding that show the training in action. He’s a grand prix dressage rider from australia. We’ve used his training and it has made a huge difference in our horses