Even so, have you proof he can do it on something that is smaller than the barrier?
I'm fully aware of what it means, but Minato was created without balance and even if he can't pull it off that with thing, he could do it with any other of Hashirama's large wood jutsu.
Special pleading much? So what if Minato was created without balance, have you seen the shit Hashirama and Madara have been pulling off? That's beyond how broken Minato could ever hope to be. And "oh, even if he can't pull it off with that thing, he could do it to other mokuton"? THAT'S THE FUCKING POINT, what's stopping that Senju Kannon from flattening Minato while he's occupied with tanking other Mokuton?
Instead of doing your silly apologetics, accept the reality: Kishi doesn't give a shit anymore about Minato, now is all about Hashirama and he makes Kaiju look subtle by comparison.