I have a 4.5 V TEC that can draw (up to) 2.85 A. Based on your WTC3243 datasheet I believe I would require a supply voltage of 6.06 V. I will limit the current applied to 2.3 A via the current-limit resistors. Based on the info in your datasheet I will be running in zone 2 (middle shade of blue) of your “Safe Operating Area” plot. This indicates to me that my design will require a heatsink plus a 3.5 CFM fan. Am I more or less correct here?
You are correct, the heatsink and fan need to be added.