I have a dragon I made that uses the same animations as the Akatosh Mount. Everything works fine, but I get frequent crashes when the dragon jumps and lands, which shakes the ground and has a similar sound effect. I'd say 8 times out of 10, I'll crash with this. I also occassionally will get crashes when I drop from the sky to land. In other words, press the Walk key to make the dragon stop flying and walk. Also, if I land hard enough to cause the ground shake effect and sounds, that'll make me crash too.

Any clues as to what could be causing this?

By any chance do you get random crashes when flying really fast with the dragon? I've experienced all of the same issues as you, but I just uninstalled the mod rather than deal with yet another headache.

Yes, actually I did. A lot of it had to do with an older version of MMM though. There was a problem with one of the spawns that would churn out 0 leveled spawns, which could cause crashes. This incidently has been fixed with the new version of MMM. Another problem is that the game didn't have time to render the objects because of flying so fast. I take it slow when flying. If I see "Loading" on the screen, I'll stop and wait for it. If I get some pretty bad FPS, I'll stop again until it catches back up. That so far has helped.

I've figured out that the crashes from the jumps and hard landing is probably due to an animation bug with my new dragon. I'm just not sure how to go about fixing it.