My main weapon is the Dapple Dualies Nouveau, and I have the tendency of relying on it for everything.
As a player who just so happens to have an aggressive playstyle, I enjoy having abilities that support me in succeeding my attacks, alongside further boosting my aggression. Because of just how much mobility you're offered with the Dapple Dualies, it's quite easy to not only achieve an aggressive approach, but it's also easier than you'd expect to shark opponents, I'd say. Even during Splatfests, I find myself having no difficulty in splatting the opponent and their teammates.
As it follows, the loadouts I enjoy using for the Dapple Dualies Nouveau are both supporting of an aggressive playstyle, though one is more situational than the other.

The first loadout consists of Swim Speed Up. On its own, the Dapple Dualies are - like I have previously stated - very good in terms of mobility, and Swim Speed Up just so happens to further boost its mobility as you'll find yourself constantly switching inbetween your squid and kid forms. With this, you'll be able to go face-to-face to opponents while having zero problems in doing so, and because of its high damage ratio, you'll be able to shred any enemy who even dares to get close to you. This loadout is overall very good for the Dapple Dualies Nouveau as it not only further boosts your chances of successfully sharking your opponents, but it also provides you a better chance of escaping unexpected attacks and better chances of infiltrating bases, which is useful for taking down enemies by surprise.
As for the second loadout, it consists of both speed and stealth, though I've found this loadout to be especially situational and its effectiveness is very dependant on the stage. You'll have an easier time getting back into the game thanks to Stealth Jump and Quick Super Jump, but even though you have access to Stealth Jump, you'll still have to be careful about your Super Jumps since you'll otherwise be vunerable to attacks if an enemy just so happens to spot you. With that aside, I'd consider this to be overall good as it'll be easier to support your teammates through your aggressive playstyle. Personally, whenever I'm using this loadout, I enjoy to immediately hunt after enemies once I land, preferably by finding a way of attacking them from behind, and getting rid of them by surprise - Ninja Squid allows you to conveniently do this. It's essentially the same thing as the former loadout, though you'll have an easier time using it if you know where your opponents are, and take advantage of your teammate's positions. Analyze the routes of your enemies, and use this information as an advantage to splat them - this applies to both loadouts.
In conclusion, the Dapple Dualies Nouveau is a very good weapon and has served me well, especially considering the fact that I like to play very aggressively. This weapon is especially dangerous on stages like Manta Maria and The Reef - you can basically strike from anywhere you'd like, so long as you know what you're doing. I've found this weapon to be very useful in most game modes, more noticeably Splat Zones and Rainmaker (sometimes Tower Control), as it's easier to support my team by constantly splatting opponents and making sure that we're meeting our goal. My favorite abilities to use alongside the Dapple Dualies are Swim Speed Up, Ninja Squid, Stealth Jump and Quick Super Jump, as they offer support towards my aggressive playstyle. If your intention is to support your team through an offensive playstyle, I highly recommend using these abilities to your advantage.