Hey Chris, also for cluster, solution provided by sk117794 (linked from sk95968 @ point 4) ) seems to be very dangerous.
Like i said inside SR 6-0003534450, any new get interface with/without topology will invalidate/delete the manually created loopback interface. The behaivoir is confirmed and no solution provided (it works by design).
so, if you add new interface/vlan and you forgot to add loopback interface again, i suppose OSPF/BGP process will be disrupted because of new Router-ID needs to be selected
I've opened a RFE number hT5Nxy49E