Hi boost Afr

My Afr in my stock map in the high boost area is super rich. It runs about 9.8 Afr. Should I be looking to go that rich in high boost about 20-21 PSI. I have tuned these cells to about 10.5 Afr. Since this I saw some knock occurring so I have reduced my timing considerably at the onset of boost in some areas and got rid of the knock just wondering if I target such rich Afr if I would be able to add timing

I'd need some more information to really advise further. What engine and fuel are you running for a start? Irrespective of this though, unless it's a rotary engine it would be rare to need to tune as rich as 9.8:1 or even 10.5:1 at 20-21 psi.