Obviously a new use of the word National that I'm not familiar with....
On the subject of released on contact I'm with what seems to be the majority view - it doesn't comply with the rules and so you're on dodgy ground if it goes wrong. And there are too many ways it can go wrong. That doesn't mean I've never done it or accepted such a release but I would never recommend it as good or normal practice. When it comes to trainees, I think it has to covered by the training so that the u/t understands the risks and implications. Advising a u/t not to accept ROC is a good idea but ultimately every controller has to make their own decisions and that should be based on a good understanding of the factors involved rather than simply being told it's not a good idea.
Released leaving CAS I have few problems with. Having worked approach for many years at an airport not directly connected to the airway system it is essentially a point, it's just that you may not know where it's going to be. When I worked in that environment NATS went through a bit of the transition from providing aircraft joining/leaving airways with a service to 'if it's outside CAS then we don't provide a service' so a lot of the releases were leaving CAS leaving APR to resolve any conflicts for joiners/leavers. Not a problem - just a bit more work sometimes for APR.