Do all inductive loads require a diode? (AIM PDM32)

I imagine that this question could be generalized for any type of PDM, but in the case of the AIM PDM32, only the 4 high output pins (20A) have internal diodes to protect against reverse current from inductive loads. I have more than 4 of these kinds of loads, so in some cases, I will need to use the low power output pins which do not have built-in protection. My question is, do I need to add an external diode for things like my radiator fans and fuel pump? More generally, what calculations are needed to determine if a diode needs to be added for any given inductive load?

I made this thread a bit prematurely – I got in touch with AIM support and was informed that the current production models of the PDM32 have internal diode protection on all output pins, including the medium and low power outputs. The documentation that I have seems to be outdated as it states that the medium and low power outputs are not protected.