Is it possible to access the Device ID of the system? For example, in swift I’ll use something like UIDevice.currentDevice().identifierForVendor. How would I go about that in Fuse?
If you’re OK with using Objective-C you can use foreign code. If you need the value in JS, use a native module. Here’s a starting point.
This community package might be of help. 
https://github.com/MaxGraey/fuse-device