I have some experience driving my friend's Lammina, and lots of experience riding in it. I think it is a 9.5, but it could be a 10, if they also make that model. He has a 15hp Yamaha Enduro on it and there is no issue at all. In fact, with 4 people in it, it kind of lugs down.
Again, his may be the next size up.
BTW, I have yet to be on a dinghy
in real-life usage that couldn't handle the max engine recommended for it. Most are dogs
with the recommended size engine.