Impact of Separation on Family and Private Life Visa (FLR(FP)) and Future Extensions

[chopwell20]

I am currently on a family and private life visa route (FLR(FP)) with my spouse and two children. One of my children is a British citizen, and my second child, born in the UK, is expected to gain British citizenship this December after completing 10 years of residence.

My visa is due for extension in early 2025, and I will have completed 20 years of residence in the UK shortly before my final extension is required. I am considering the possibility of separating from my spouse, and I am concerned about how this might affect both my future visa extensions and my spouse’s immigration status. I would like to know:

How would a separation impact my FLR(FP) visa, particularly in terms of the family element of my application?
Given that both of my children will be British citizens, could my parental relationship with them still support my application under this visa route?
What effect would separation have on my spouse’s visa, considering she is currently a dependent on my visa?
Would my eligibility under the 20-year private life rule be impacted by this change in family circumstances?
Any advice or insights would be greatly appreciated.

[meself2]

I will have completed 20 years of residence in the UK shortly before my final extension is required.

Why does that matter?
As far as I know, it's 20 years of illegal stay to be able to switch to legal stay (so would be 20 years in total), but you already have a visa.
How long have you been in the UK legally /without breaking continuous residence?

[chopwell20]

i entered legally, but due to lawyer negligence case was struck out and i had no option but to overstayed - there was gap of no contact with ho of about 3 years then been writing to them for considerations out of rules which were also refused.

in short we were granted 10 year flr fp end of 2018 but i have been in the uk since 2007.

Thank you .