This is obvious when you think of it, but you might not think of it.
When recording BBC 1, it is better to record from BBC London (or BBC NI) than other regions. This is because doing so will allow you to also watch BBC 2 London, BBC Three, BBC Four and Five if you record something else at the same time.
Similarly, recording BBC 2 England (rather than Wales, Scotland, or NI) will always give you access to BBC 1 London (or NI), BBC Three, BBC Four and Five.
When recording BBC 1, it is better to record from BBC London (or BBC NI) than other regions. This is because doing so will allow you to also watch BBC 2 London, BBC Three, BBC Four and Five if you record something else at the same time.
Similarly, recording BBC 2 England (rather than Wales, Scotland, or NI) will always give you access to BBC 1 London (or NI), BBC Three, BBC Four and Five.