Hashirama was incapable of using myoujinmon to bind EMS Madara's kyuusanoo, how is he going to do the same to a far more mobile construct?You've just shown me Naruto and Sasuke advancing towards Juubito and nothing more; that doesn't show Naruto's fast enough to evade Myoujinmon in the Avatar, not when it has feats of immobilizing someone as fast as Madara who's definitely faster than Naruto's Avatar [You must be registered for see links].
Hashirama couldn't even immobilize madara when he had his mokuryus wrapped around and draining madara of chakra, the only reason he landed them was Madara getting obliterated by SM Chou oodama rasenshuriken and then being immobile and practically helpless while his edo body reforms.
How does Hashirama do that before BSM Naruto shunshins out and puts up another avatar? Mokuryu got blown to pieces by a BM Naruto shunshin, and it's at best as fast as BM Naruto's avatar, how is it going to restrain BSM Naruto? A single FRS would destroy that. Mokujin isn't grabbing something as fast as BSM Naruto, FTW doesn't instantly knock people out, nor does it instantly cover the terrain, and Naruto doesn't have to bust the whole technique, only a portion of it like oonoki did, something that is possible with a KN4-KN6 bijuudama.They'll always need to defend considering Hashirama will have multiple Mokuton constructs out. He takes down the Avatar, then Mokujin takes him down, or Mokuryuu comes at him and restrains him, stopping him from moving all while absorbing his chakra at the same time. While Naruto's in the process of deactivating his Kurama Avatar, Hashirama can also put up FTW which will be effective since the only thing that can be fired fast enough to take down FTW before it releases pollen is a Bijuu Bomb, and Naruto can only make large Bijuu Bombs while in the Avatar. FRS is capable of taking down FTW but it needs a bit of prep time to make it big enough to destroy the Mokuton [You must be registered for see links][You must be registered for see links].
BSM Naruto was in hashirama's tier, I don't understand how you got the idea he wasn't. Sasuke's PS enhanced by naruto's bijuusennin mode could possibly be as powerful as Madara's, and at the very least is in madara's tier. Hashirama had all the reason to use myoujinmon against Kyuusanoo as it would have rendered the beast completely helpless against Shinsuusenjuu which would have resulted in a low difficulty win for Hashirama.Feats. There's nothing that implies Sasuke's PS is as powerful as Madara's. Naruto resembled Hashirama but he still wasn't as strong as him as feats have shown, so I've got no reason to believe Sasuke, a person who resembled Madara, is at his tier when Naruto wasn't at Hashirama's tier. Hashirama had no reason to use Myoujinmon when Shinsuusenju was sufficient enough.
Edo Hashirama also had all the reason to use myounjinmon against edo Madara's PS, yet he didn't. This shows that with enough reactions and speed, myounjinmon isn't landing.