I’m checking on the power consumption table. All functionality is there across the voltage range. So it has nothing to do with limitations at certain voltages. That said, I’ll let you know what I find out.
I want to add some clarification about what the developer guide stated regarding 5v on the Dragonfly. There is a jumper on the board “TARGET VOLTAGE” that can be used to set the voltage supplied to MDOT or MTSMC types of devices to 3.3v or 5v. That jumper does not apply to the Dragonfly. Dragonflies will be powered by 5v unless you get a bit more creative and place a jumper from the 3.3v pin of the “TARGET VOLTAGE” connector to the appropriate pin of the 2 pin connector next to the Dragonfly connector.