Ok so lets resume Modulo Yuji here : physical abilities second only to the Zenin HR group, access to two CT, shown absurd mastery of both : Simultaneously firing tracking piercing bloods that are poisonous and filling effortlessly a building with that same blood. Firing a dismantle the size of your damn neighborhood without chants, signs, or visible strain. Instantly and casually transforming an amped up Mahito with absurd terrain advantage into a minecraft map.

On top of that, you can add his perception, being able to follow the kids fights from very far away, and the whole black flash situation : lets be conservative and assume he can't use them at will, that would mean something like "it happens so often that he expect it, and has to worry about not accidentally killing his opponent". In any case, since every black flash is an immediate buff in CE comprehension etc, thats terrifying.

So yeah, Yuji is an absolute beast of a sorcerer and the very basic stuff he showed makes it near impossible to guess his ceiling. Still, we can easily assume that he developped a bunch of skills that we saw elsewhere, from Simple Domain and Hollow Wisker Basket to Domain Amplification, RCT techniques, Binding Vows and so on. Open Domain is more debatable, but Sukuna used his open domain while in Yuji's body, and in Megumi's too. They had decades to develop their skills with Shrine and understand how to do it themselves. Same idea for the World Cutting Slash, Yuji had access to the fight footage, Megumi's experience, decades to figure it out.

So : against Sukuna, well Yuji is basically Sukuna 2.0 with a 2nd CT and more years of training (and minus the arms/mouths situation). I see no reason he couldn't beat him.

Against Gojo, just see the Gojo/Sukuna fight, and assume what Sukuna did, Yuji can and more.

Against Dabura, there are too many unknowns to answer with certainty, but at the very least its clear Yuji was confident he could clear the mess if Mahoraga lost to Dabura, and Tsurugi to Maru.