A toggle would be great, one thing I don't like is when I'm trying to use a mount to run on the ground and the second I touch a wall it changes into fly mode....
It would really help to add a toggle to prevent mounts from flying. Very easy and simple quality of life that only takes coding on the client side of things (I think). It would just be a client side lock that would prevent the game from sending a "fly" request to the server.

I support this QoL.

Also, let's try to be considerate, not everything is troll. Thank you for the suggestion OP, I agree with it.