God damnit, even as clean as i tried to be a small aluminum debris got squished on a main bearing non grooved side (bottom of the engine). I tried to remove it with a sharp thin box cutter and got it out but left a tiny hole. The sharp edge took out a bit of the bearing, ill say its about a 0.5x0.5mm lil hole, depth: it isnt really deep but i do think it went through the coating and the first layer of the bearing, dont know if copper is seen.
So im wondering if it matters really, i think it wont affect the general oil film but i dont know if im risking delamination from that small gouge.