You can be compelled to provide fingerprints based on a warrant; I'm unsurprised (and not particularly bothered) that you can be compelled to use them on your own device.
I thought that fingerprints were to be provided to:
1) establish biometric proof of identity
2) establish the presence of a person in a particular place
3) establish a person handled a particular object
Or does the law establish that the authorities can use fingerprints for evidence in any fashion? Could they use a scan of a fingerprint to etch a fake-fingerprint latex sheet to open your locked device?
I'm not sure where you're getting this list from. But, I think that #3 would be relevant in this case, as the person would have needed to handle the device to register their fingerprint.
Sorry, I guess I just read your phrasing to have more authoritative intent than you were going for. As I (also not a lawyer) understand it, there's nothing in particular that limits how intermediate/circumstantial pieces of evidence can be used/combined to find more evidence as long as each piece of evidence in the chain was acquired legally.
I thought that fingerprints were to be provided to:
Or does the law establish that the authorities can use fingerprints for evidence in any fashion? Could they use a scan of a fingerprint to etch a fake-fingerprint latex sheet to open your locked device?