Hey Brian,
I agree, in most situations you’re probably not going to need a heatsink for a board with that rating. However, they still have some losses and we’re talking about a pretty substantial difference in voltage (relatively speaking). Since we’re not sure about the environment the board will be exposed to it may not be a bad idea to add a heatsink anyway as there will certainly be at least some heating from the converter particularly if you’re drawing current to the peripherals of the Pi, and it won’t cause any issues by adding it. All the best with the project Tom!
