When to make a new record
Very rarely! That's the point of integrating entry.
General principle: make a new record when there is a new resource/work rather than another iteration of the same resource/work
That is, when there is:
A new integrating resource
A merger of other resources (12.7B8b)
A split of an integrating resource into other resources (12.7B8c)
Original URI is still active but original resource is no longer available (Rev. LCRI 21.3B)