Not exactly sure what you are looking for, and what type of device you are using as the headend. How are you assigning IP Addresses to RA VPN clients? If you are using DHCP you can modify the default GW there. I am not sure I follow your routing table concern. If using an ASA you would need specific routes there as you feel are necessary. Clients would route traffic through the ASA via their respective assigned GW. I would assume that you could add static routes locally on a client if needed and that would work in certain split tunneling scenarios. Note that within your group policies that are assigned to your connection profiles you would configure split tunneling there. Not sure if this helps. Good luck!
