L3: effective width of FMC_VREFA_M2C and FMC_VREFB_M2C polygons
Even if they are quite thick, their effective width is quite limited by vias around X:91.2mm Y:57mm. There is space in both directions, both FMC_VREFA_M2C and FMC_VREFB_M2C can be expanded a bit in this area.