In my opinion, everything is much simpler, druids in fly form on the ground, they just fly slightly above the ground with 100% speed or they can sit on the ground, here you can just do the same.
It will violates the basic rules of the game, dragons will simply run away at the first opportunity.)
Soar has an advantage over other flying mounts because the take-off launch doesn’t use up any Vigor, so I hope they do not change it. Steady Flight is a relic and you can just use a regular mount for that.
oh, yes, steady flights a relic but much slower, here’s an idea… change soar so that it can be used without dismounting on the ground like the Worgens own racial mount ability, then the Dracthyr doesn’t take off, change the soar to use 1 vigor when it takes off or not since the Dracthyr are HUMANOID DRAGONS, it isn’t exactly an advantage to have a single extra vigor nor should it matter since the only reason it would is to get to something faster.
And druids won’t? 
Would love to have Soar work like flight form.
A great compromise would be to make soar an empowered spell cast. Instant cast is just flight form. Charging it up makes you soar higher based on charge.
Would have to allow it to be instant cast mid air as an empowered spell though.
Bonus points if the initial dash based on charge time was in the direction of your camera so you could look up for a normal soar upward flap. Or face forward for a free whirling surge kinda like superman taking off
I’m fine with soar the way it is but this is hands down the best suggestion I’ve seen for a change.
You’d have to iron out how the empower would work with “press and press again”, though I suppose you could just force that one specific empower to be press and hold and it wouldn’t really matter since it’s a non combat ability.