To be honest, we'll have to wait and see if Eri is able to do this or if she needs a recharge after fixing Mirio's quirk.
And a senzu bean is even better than Dende.
Agreed on all of this. Nana and the others need to give Deku and big old exposition dump and letting him stew in healing juices instead of fixing him instantly might keep him from just running after Shigaraki to try and save him.