I have some basic suggestions for small improvements. Feel free to add your own ideas or feedback for what is annoying.
For the springer mount. I was rolling around and comtemplating if i should unlock the kangaroo skin and was much enjoying the thought of a powerful hopper, meanwhile i was doing that i was doing dragonfall meta and climping across the spine for weak points. It hit me - that is exactly where a beast that was a powerful hopper should shine, if i could just keep making basic hops 2-3 higher than other moutns i would roll right over that spine. However, springer just makes tiny jumps if you dont put the space in action, and i think it would be thematically fitting if springers basic jumps very a fair deal higher than currently - it really slows it down that anything you gota make any semi jump you gotta start charging up even for a small jump.
Griffon. It is very hard for me to pinpoint what exactly is off about it's movements, but it feels supremely clunky if you don't have a long distance to make a smooth motion. I realize without specifics it's hard to use the feedback so i tried to find out what was most annoying about the movements. Basically, when you takeoff just need a little heigth/forward then down, small jump up and abit ahead, it locks you into going way forward before you can start down and you end up moving quite a distance and cant hit the area right in front of you at all, so instead you use only up and when its up move abit ahead scared, it's not very intuitive to use and often leads to fails and falls down and need retry for something that should be basic. If it was a real animal it would easily be able to decide how soon exactly it wanted to start going down after jumping up, without locking itself at all. In addition if im pressing q for it to go down immediately after launch, don't completely ignore that i pressed that if it was locked in it's start up animation execute it as soon as it can instead of requiring me to press q again to register at all. If im keeping it pressed after launch its because i want it to use it asap not to ignore it.
Generally make them slightly faster to turn it feels quite clunky if you need any type of precision. Not much, it's interesting that they are mechanic and not just free control, but i think it's been taken too far even the animals would never be that stiff - it feels artificial. Also try not to animation lock them into a clunky movement like what happens with griffon, i have a feeling it happens with others too.