Setting ONLINK flag for arbitrary routes

Hi Is it possible to set the ONLINK flag for arbitrary routes? The use case is a common setup in mesh networks: All devices have a /32 assigned to the interface and advertise this as the nexthop for v4 routes. The routing protocol then installs all kernel routes as onlink, allowing routes to be installed even though the nexthop is not in the same subnet as the local link address. Is this possible to configure in Bird currently? -Toke