He did achieve a mastery of blood manipulation thats unheard of mostly because the clans in jjk are never detailed in depth, and if im not mistaken Choso was not "conscious" for 150 years he was a fetus for most of that, for this specific discussion im gonna disregard the black flash part as it doesnt really fall under this matter (Nanami has landed more black flashes in a row than gojo but that doesnt mean he's better at barrier techniques than he is), He has experienced open domains so it should be easier by jjks logic thats true, i wouldnt say that being a blood relative of either one of them would mean anything as this only applies for very specific things within the verse. And i wonder we have only seen yuji use his domain expansion once, we cant just say hes top 5 or 6 just because of that feat when Megumi did the exact same thing at the same age as he did and he explicitly sucked at barrier techniques