Question about Act 1 point of no return

[Coldhands]

I've done all of Grymforge and I'm ready to advance to Act 2. If I take the secret passage from Grymforge, can I still do the Gith Creche and any mountain pass related areas, or would I need to turn around and go take the exit from the Nautiloid Crash Region?
Trying to miss as little content as possible.

[Coldhands]

Bump

[Gameer4life]

You can go to the shadow curse land and back to the act 1 area. Only the Teiflings from the druid grove is relevant there. The point of no return is after the shadow curse land. you can go back and forth from the shadow curse land and act 1 areas.

[terror923]

The game will outright tell you if your about to progress acts. I dont know the exact prompt but it gives a notice.

[Mizu]

You don't lose access to old content until you go and interact with the Nightsong.

[Morgian]

The point that hacks off act 1 is when you visit the Shadowfell.