MN1 delay and current visa expires - risk of overstay

[testinguk2010]

Hi admin

This forum is great for all the visa aspirants. ton of thanks!

Have small query, please.

my son born in UK in 2018 and currently in UK on PBS dependant visa valid till march (my cos expires in feb)
I have recently got ilr. Yet to get ILR.
My wife yet to apply for ILR(slightly complex application)

now i need to apply for MN1 for my child.
i heard it takes a minimum of 3 to 4 months for the registration
If I apply in December, definitely he cannot be a British child before the end of February/March 21.
so while Mn1 is in process, my child visa will expire in March 21.
It means will my son fall into overstayer if the result of Mn1 doesn't come in the next 3 months
i heard it may have practical consequences as a child is under the age of criminal responsibility.
hence seriousness of overstaying of him is concerning me

also, a nationality application, such as an application to register as a British citizen, is not an application to vary leave. as such, s.3c is not triggered and my child may become an overstayer

can i have to apply for an appendix FM dependant visa for him in December to avoid the above risk?

or do you feel can i stay apply Mn1, in that case kindly share me and any supported links please that he is not an overstayer though he is PBS visa expires at the time of the Mn1 application process

[CULLINAN]

You have already been answered in your previous thread.