"the problem of how to safely get from NEPN to Roseburn Park"
Exactly.
When I'm kiddy transporting, coming from Roseburn Park heading to NEPN, I take the fiddly route round the back of Roseburn onto Russell Road and then up the zigzags. Not remotely a direct route and has moments of increased risk (although not as bad as going on the A8).
The proposal would make this straightforward and even allow us to stop for a cake.