It is not easy (by means of changing configuration or easy scripting) to set up Racoon to establish transports or tunnels for IPsec traffic upon booting or activating a network interface (acquiring an IP address).

Transports/tunnels are dynamically started when traffic apears. As a side-effect, first several packets of communication are often dropped, which is bad. Even if that was fixed, there will still be significant delay.

Some tunnels are intended to be run whenever possible, while others are better served on-demand.