Feeding a yellowing plant high P nutes is just going to make it yellow faster FYI. If you want it to not yellow because it's hungry, you gotta give it a higher ratio of N than P.
FYI, some OG Kushes like a very acidic pH. OG Kush has some very finicky phenos. Yours is doing very similar things to what the last og kush I grew did. I fought problems all the way through flower on my OG she barely had any fan leaves that hadn't yellowed by 8 weeks I ended up just cutting her early she smelled nasty too... not a keeper for me. That's why I like TGA I've never had a TGA plant that does that kind of shit. My guess is it's a finicky OG pheno or a pH/lockout issue, though that seems unlikely... have you pHed your tapwater? pretty sure if it's around 9 like my tap that might cause issues even for limed soil
I use super soil but I still pH my water I just don't trust it otherwise
pH to 6.5 in veg and 6.8 in flower for SS. You will NEVER have to worry about 'is this a pH issue'.