Great initiative. I took the 2020 Prelims, not sure of qualifying. So, preparing in an integrated manner.
For 2021 :
Oct-Dec: Optional both papers(With note-making and PYQ practice(30%)), Mains answer writing practice
Jan - March: Optional Test series(Maybe) + PYQ practice, Mains Test series
April - June: Prelims prep with Test series and PYQ papers
