If someone advice to use some buffer, I'll use it. It's not "buffered route" anymore... hehh.. I'm not very experienced in chemistry but I take advices from people, if it matches what I've learned from papers or I just don't know. But I say it is good to buffer the solution to get the peracid little bit less aggressive oxidant, or another words, little bit less active. To put little break, so the oxidation doesn't give side products, like you said you have some unknown shit in it (I don't know right words or the whole mechanism). In Rhodium Chemistry site has the procedure that I follow, but in there it is used to make MDMA, but that procedure can be used to P2P also.
Or any other ketone... It is said there that you should try to even use 25 g of sodium acetate to make the oxidation smoother reaction. I just use carbonate. I think that's why I get 85% to even straight 100% molar yield, when I make the reaction neutral, or close to neutral. Because now I had 75% yield because I had some "overflow" with my sodium carbonate, and therefore parts of the carbonate was all over my lab's tables safety glass. So, the mixture was bit acidic. And I noticed the product was red, because of that. When I started to hydrolyze it with a base, it turned yellow in the beginning of hydrolyzation. That observation of mine confirmed that I was right.