If you recall, Ceasar’s work on SAD is due to the manipulation of the Lineage Factor, which allows them to understand exactly how devil fruits work and how they are transmitted. Judge and Dr. Vegapunk worked on this together, prior to Vegapunk being arrested.
Judge then used this research to create Germa’s Clone Army – an army of the best fighter, cloned several times over. He then used this to some more extent to manipulate Ichiji, Niji, Sanji, Yonji and Reiju. Stripping out elements which would grant them emotion, giving them an exoskeleton, and granting them all superpowers.
It is worth noting that while Sanji had the procedure fail on him, manifesting emotions and all that, he is still said to have power on par with the Vinsmokes and has gained the ability to summon fire on demand. No link has been drawn so far, but Sanji’s fire powers have always raised an eyebrow, even in the New World.
Regardless, the remaining Vinsmokes all have powers which resemble devil fruit powers. Yonji has extreme super strength, Niji is a paramecia Enel, Ichiji is a Paramecia Kizaru while Reiju is a Zoan Magellan from the looks of things. Instead of eating devil fruits or SMILEs, perhaps Judge simply applied the research and changed the things that the Devil Fruits would have changed anyway.
Oda also brought this up as a joke: “Sanji has swirly eyebrows, devil fruits have swirly patterns, so Sanji is a devil fruit lol.” On one hand, it looks like a joke, on the other hand, Sora Vinsmoke does not have curly eyebrows. Judge’s eyebrows are hidden. All the other Vinsmokes DO have curly eyebrows, and they’ve all been subjected to genetic engineering.
Now, that we’ve gotten more on that, let’s draw a line:
In Alabasta, we learned that inanimate objects can eat devil fruits.
In Enies Lobby, we learned that this is due to Dr. Vegapunk, who knows how Devil Fruits work.
In Sabaody, we learned that Vegapunk made Kuma clones and has given them the power of Kizaru’s lasers somehow.
In Punk Hazard, we learned about the existence of man-made Devil Fruits, the SMILEs.
Afterwards, we learned about the Lineage Factor.
In Whole Cake Island, we learned they can give people powers, and got exposed to a fighting squad of people with altered lineage factors.
In Reverie, we’re now seeing Dr. Vegapunk has finished working on “something” big.
Oda has left a trail of blood line elements and devil fruits throughout the story, I think we’re close to a big reveal.
*Theory by throwingthissway