I ran into this and was able to complete it with just the gryphon and hopper. It was a huge pain but I first used the gryphon to the first platform, then with the hopper I started to jump but hit dismount right before actually jumping, so that I was thrown into the air, then mounted my gryphon at the top of that jump and was able to get to the next platform (barely), I tried to repeat that again but I failed and fell off the platform so and instead just flew with my gryphon under the remaining platforms, diving and climbing as much as possible, and it counted it completed when I got to the end, even though I was below the actual end platform.
I ran into this and was able to complete it with just the gryphon and hopper. It was a huge pain but I first used the gryphon to the first platform, then with the hopper I started to jump but hit dismount right before actually jumping, so that I was thrown into the air, then mounted my gryphon at the top of that jump and was able to get to the next platform (barely), I tried to repeat that again but I failed and fell off the platform so and instead just flew with my gryphon under the remaining platforms, diving and climbing as much as possible, and it counted it completed when I got to the end, even though I was below the actual end platform.