You want to kind of Base your time frame off of when they internally pip. Refer to
@Pyxis guide.
https://www.backyardchickens.com/threads/living-off-social-security.1272852/post-20463226
And just go with your gut.
As long as they can breathe and are tapping chirping and being active there is really no set time.
In theory they should be fine as long as they can breathe.
It can take quite a while from internal to external, maybe more than 12 hours. But it's all up to you really on how long your willing to hold off opening them.