My PIO dated 10/24 has been approved yesterday and I have collected it from CKGS during the pick up time yesterday as my travel is on 11/21. ...

Yes it takes 48 hours to get the passport back. I am not sure abt visa at port of entry.

I went to CKGS to withdraw my passport and apply for urgent visa, from what they mentioned , each of it take 48 hours so effectively 4 bussiness...

you mean the pio application. My pio application dated 10/24 is there with them and they didnt recommend me to withdraw when I called them ...

What additional documentation do you need to provide for urgent visa? Do we need anything like doctor certificate, etc.