Pokemon Sun / Moon speed up gameplay
Solution 1:
I've looked around and I can't see anything other than what you have stated.
The only other way to speed the game is that you get given a Pokemon which has the ability to fly, flying around the map will significantly increase the game speed as it cuts down on all of the mindless walking you have to do to get around.
There is no bike in this game, however.
I apologize that I couldn't be much help here, I just don't think there are any other settings to speed up game, other than the ones you are already using.