Recalbox is not include in CASE MANAGEMENT the Hat Recalbox RGB Dual, so, the 4 options showed don´t work.
Why? because Recalbox RGB Dual use GPIO 26, it is not usual for Fans beacuse is not a PWM pin, so the fan works as ON/OFF, is not progressive, but better than fix the fan to 5 or 3.3v.
To do it you need to add this in recalbox-user-config.txt
May be the recalbox masters can add Recalbox RGB Dual Hat in CASE MANAGEMENT options in the next update 🙂