ILR through Tier2 migrant route (missing PSW BRP copy)

Hello All,
I am in process of ILR application by super priority Sopra service hoping for a quick decision.
2 queries
1.
I am hoping I can resolve document requirement of this

For the period before you were granted leave as a Tier 2 migrant, documents showing that you met the
relevant requirements of the immigration rules. For further information concerning the evidence required,
please refer to the Tier 2 migrant policy guidance on our website

I cannot locate any copy of my Post study work BRP which was my status before my first Tier2 application(in country, UK). But I have the letter I got with PSW BRP which states the number. I also have further communication letters from home office acknowleding my application for PSW, letter asking to submit biometrics for the PSW visa and my first Tier2 application form which has PSW number. I also know the start and end dates of my PSW.
TLDR - I have all information about my Post study work visa except a copy of it.
Can you advise me if this will be a documentation issue?

2.

There is a difference of 3 days between end date of my PSW(5th March) and start of my Tier2 General(8th March). But I have my biometric(for Tier2) letter acknowledging my application for Tier2 before PSW expires. In this way I can prove I made my application for first tier2 well in time.

Anyone in a similar situation can shed some light?

Thanks,
Ganesh

It is NOT required for ILR based on Tier 2 only.

It is required if you are combining Tier 1 General/Entrepreneur with Tier 2 to make up 5 years for ILR.

Thank you.
I interpreted the requirement as "Prove you were legally in UK before applying tier2 general by PSW route".
I am happy if PSW BRP copy is not required at all.

Regards.

You are interpreting it wrong.