Seeing a 80-smoething long feature movie with Jake, his maternal family and best friends fighting some other magical threat.
It could have been taking place between the season 1 finale "The Hunted" and the season 2 premiere "Half-Baked", like some time before Rose had left to stay at the Huntsclan Academy, with her as the newest ally as she has romantic feelings for Jake that are just as strong.
Like, just how did Lao Shi's wife finally die? We could have seen in flashbacks and pictures, and what her human and dragon forms had looked like, and how she fell for a younger Lao Shi the Chinese Dragon during the 1980s or something.
Besides, I really hated that they changed the Huntsclan color from dark green to maroon, and making Rose/Huntsgirl much more slim and thinner than she is supposed to be!
Or even a second feature movie set after the finale, in the rightful original animated design, in which Jake helps Rose in finding what happened to her twin sister; their parents (learning their first and last names) finding out that Rose was destined to become a natural dragon-slayer.
And even Jonathon's help at times, now that has accepted his dragon wife's magical family secret.
And us seeing other places in the hidden mystical realm in addition to Drago Island.