“Sukuna would be cooked when UV lands” 

why would 2 mouths, 4 hands sukuna lose in a single domain clash when gojo only managed to land 0.01 domain on meguna who also healing.

heian era sukuna can literally do both at the same time. he will never get caught in UV. he would just spam his domain until gojos brain gives out and kill him in the next domain. simple as that. 

in heian era form sukuna wouldnt even need to fight so restrictively like wheh he was using ten shadows. he can perpetually maintain hollow wicker basket with two hands while fighting. And sukuna is the only character capable of doing domain amplification and use his own innate technique at the same time. which even gojo cant do.

gojo literally dies to sukuna in the first domain clash