Yes, a properly functioning relay should not make any metalic rattling noises, BUT, if something inside is loose, maybe it would. (A relay is electronic, so it's got to have metal inside) I don't know. Like I said, just throwing it out there.
Other things could be loose inside the unit; magnetics could be causing a rattle when you transmit, perhaps.
Have you popped the top off, and tried to isolate the source of the noise?
If your 2970n4 was doing similar things, prior to dying, this may be cause for concern.
As to staying safe; always the plan! You do the same. I note that you are in Florida. Might I suggest that now may be a good time to go visit a small town in north-west Alabama, that no one has ever heard of? (Skip Atlanta; that's where the rest of the state wants to evacuate to, lol)