sysctl's are not free and in this case you want to add a second one to
pick and choose which data in the message you want the kernel to act
on.
Why can't the userspace daemon remove the route and add the one it
prefers? Or add another route with a metric that makes it the preferred
route making the kernel one effectively moot?
As I recall, kernel was adding back the prefix based route when it is
deleted by userspace. I'll check this again to confirm the behavior
and also try installing the routes with lower metric.
