Well, this will obviously be a 4 layer board, but I can say with the MEBv2, we had tremendous problems with thermal dissipation of the LM2576 at 9-12vdc, at 6vdc is was manageable, but the MEBv2++ are 2 layer boards, and with the addition of a secondary power plane, it would probably have been fine. For the most recent versions, we are using an AP6503a, and so far at 6, 9,12 vdc the heat is non-existent. Not to mention, the local price of the AP6503 was .60c cheaper than the LM2576, and is 85-95% more heat efficient.