I think a South East board is a good idea. The South East Region of England (which doesn't include London) is England's most populous region and it's also more populous than either Scotland or Wales. It's famous for its wonderful countryside and has two national parks: the South Downs and the New Forest.
Yet here the entire region is part of the Rest of England. I think that might reflect the notion that walking is what people go somewhere else to do - a holiday activity - rather than it being something to enjoy anywhere. Just a thought...
There are great walks in that area. I am originally from Southampton and have often walked in the New Forest. The Wayfarer’s Walk, Test Way, Itchen Way, Forest of Bere and the Meon Valley are all worth walking, as is the Isle of Wight.