Zen 16 multi relay - power another device via USB?

[calinatl]

A Zen16 multi relay is installed in a somewhat inconvenient to access location, so I'd like to figure this all out before crawling under there.

Basic question is whether the USB port on the Zen 16 is one way in only - ie only used to power the Zen 16, OR can it be used to power another device - ie if I plug a device into the USB port will the Zen 16 power that device?

[ETA: I have the Zen16v1, with the 500 chip, in case that makes a difference]

Current setup is a Zen16 powered with 24v from the controls terminal of a whole house dehumidifier. This has worked great for over a year now, so I'm quite thankful. This means the USB port on the Zen 16 is not used.
This is the wiring diagram:

and this is the thread in which the setup is detailed:

Automating a manual Humidistat with this relay? thoughts

Thrilled to have found this thread, because I also would like to control my whole house dehumidifier via zwave, but in parallel with a wired dehumidistat powered from the dehumidifier controls. Noodled through this enough to conclude a Zooz Zen16 would probably do it, but have not figured out the details... If anyone has figured out the wiring setup and Hubitat rules for adding a Zooz Zen 16 in parallel to control a Santa Fe whole house dehumidifier with a DEH 3000R De/humidistat, any info you…

[JasonJoel]

It is used to power the ZEN16/ZEN17 only.

Never connect the USB port and ac/dc input at the same time. It will back feed the higher voltage from the ac/dc input into the usb connector.

EDIT: feel free to ask Zooz support, they are very helpful, but I am confident that they will tell you the same thing.