I've tried every game I could find for dragon battles, free, borrowed, or purchased. I eventually wrote my own.
In every case, the rules didn't work like I wanted. I never got the feel I was looking for.
I have not tried those Sky Dragon rules, but since they're based on a starship game I don't see how they would be much different than the other starship mods I did try.
The issue probably isn't the rules, I'm sure it's more me and what I'm expecting from them. I hope you do find what you're looking for. I would suggest taking a moment to define to yourself what it is you're wanting. What would make it a dragon game in your opinion?
If you do find something, I would love to see some AARs!