So I have a feeling people might not like what I’m about to say… but I think devil fruits should have to be mastered and thus abilities progressively become available.
My basis for this is that many characters in the show had to train with their devil fruits to unlock/create their abilities. The two main examples I think of are Brook, robin and Luffy. Brook has no abilities outside of walking on water pre time skip however now he has learned to not only control his own soul but control other souls. Robin couldn’t make giant versions of herself until after the time skip, and now she even has her demon child form that she just used to beat Black Maria. Luffy couldn’t use gears when he was a kid, he has to come up with them and progressively get stronger to implement them.
The point is I think we should have a point system similar to doriki called mastery that shows up when you eat a fruit. Idk why but I think 4000 should be the max (it’s a random number). As you use the fruits abilities you get more mastery points, this will allow you to unlock the more powerful and intuitive abilities. This is something that should be case by case. For example zoans should always be able to use both forms once they eat a fruit. Gomu users should maybe be allowed to use the base moves but no gears. So the order isn’t based on the list currently in the game but based on how strong the move is, or the order the actual owner unlocked them in the show. Depending on the fruit you might have more than one ability unlocked or all of them. It’s also about how complicated the move is. For example, there is no reason why hie wouldn’t be able to use ice age from the start because it’s a pretty straight forward ability, whereas Gear Second isn’t something you would know right away
This can be a config option where when turned off eating a fruit gives you all its moves but when on stronger or more intuitive abilities will require you to unlock them.