Nice work intron. In this thread we talk about the final psu stage and chip itself, this is somehow wrong approach cause if we think about for the lowest parasitic parameters of the circuit without knowing the main power supply with its voltage stabiliser we can make them oscillate and emit noises because of the to low z load, so it will be good to discus also a simple power supply for a single chip. Your desing is good for cooling as you have mentioned above, if we want to acheave some better parameters we can stack bypass capacitors one on top of the other but this technique will again affect cooling performance I think that your pcb is quite good if we think just for powering up the chip and measure some parameters it will give as enough knowledge for further development.