I’m in the process of applying for ILR after 5 years of Tier 2 General (now PBS Skilled Worker). My wife recently joined me on September 2020 so she is obviously required to extend her current dependant visa. My question is whether I should switch her visa to spouse visa or should I extending her current PBS dependant? My concern is the extended dependant visa will only last for 3 years which still not enough to qualify for ILR. Once I got ILR I will likely got a new job so wont be able to use the current sponsorship number.
Another question I have is about my child who was born recently on 16/08/21. She has 42 days to register her birth but since I will apply for ILR in the early September, I wonder if it is worth delaying the birth certificate to get her British citizenship once I got the ILR? I know she can use form MN1 to do so later but it will cost £1k

Many thanks!