[Jasondaws712]

One thing to note is when doing a refund directly with apple is you MUST NOT turn the devices on as apple is known to check devices

^ This.

In terms of the Apple Watch, they have the capacity to check the activity on the device - whether It's turned on or otherwise.

I'd like to add to this - in no way am I doubting what you're saying and I do agree that you should never use any device before you receive your refund, but I recently EBed an Apple Watch in-store after I'd turned the device on and the SE was still a success, though I assume this was because I was in-store and they didn't have the capabilities to check the device status there and then.