Father of irish citizen stamp?

Hi hope everyone is doing well. I just need some help, I am a stamp 4 base on my parents citizenship. My husband just arrived in Ireland and going to register for his IRP card, so I believe he will be put on Stamp 3. We have an irish citizen baby, and which I know you can get stamp 4 off your irish citizen baby if you have an existing IRP card, my question is how long does he have to be stamp 3 to change his stamp? Or can he change his stamp as soon as he gets his stamp 3 card? Thank you.

He would get this Stamp 4 straight away (as long as he provides the documents to support his Zambrano upgrade). For more information, research about Zambrano.