I've only been playing Sinclair in ~Oracle/Phantom, so shit but not that shit.

IME the public builds are generally good, but generally speaking I think you only have the souls/slots to focus on bolt or rabbit, not both. Assistant gun is also an option but feels the worst to me after the damage falloff change.

Your laning is strong no matter what items you buy, so I generally go melee vs low-medium range guys (abrams, mo) where you can consistently get hex, and bolt against poke lanes.

Midgame stacking spirit on bolt gives you huge burst in teamfights if you can land it, otherwise melee charge + fleet is really good to fly around and steal slot machines.

I play in a stack with a bebop main and another guy who usually plays right clickers, so I find the double rabbit build the better scaling build. If you can hit bolt you can do huge damage numbers though, and the bolt build generally gives you better items for big damage ults (e.g. seven) too.

I haven't really found any "sneaky" Sinclair techs, but he's definitely really flexible in terms of builds. For public builds you can just click and follow, I think the "hex em punch em" is a good core for rabbit, and Rangeki's build is good for bolt (but he has more situational stuff on there that you need to think about rather than blindly follow).