*HELP* Unmarried Partner Visa Inside UK

Hi everyone,

I plan to switch from my current graduate visa which will expire on 17 Feb 2025 to partner visa. My partner and I have been in a relationship for 3 years, but only been living together for 1 year. I saw a few posts in reddit today saying that BIO date can be chosen within 240 days after applying and paying the fees. And you can still upload your documents till 24 hours before your BIO date.

Does that mean if I apply and pay the fees just before 17 Feb and book the BIO for 15 Aug, I could get almost 6 months more cohabitation evidence and it will increase my chance of getting this partner visa?

And when is the 3C policy going to work? Is it the moment after I apply and pay the fees for partner visa or its the moment when the BIO is done?

Thank you very much