pfSense

I have pfSense with 2 WANs (ISPs) and L2TP server on it in head office (HO). I RDR 1701/udp to LAN address of pfSense from each of WANs in HO. Each branch office (BO) connects to both external IPs of HO via L2TP. I selected LAN for L2TP server's "Interface" in GUI (HO), but it I see via sockstat that it still listens on *:1701. Session from BO to WAN1 (default gw) of HO established. Session from BO to WAN2 of HO fails with this error:
Jul 12 01:01:05 l2tps: Incoming L2TP packet from 178.173.20.227 33450
Jul 12 01:01:05 l2tps: L2TP: connect: Address already in use

I added LAN ip directly in mpd's config (/var/etc/l2tp-vpn/mpd.conf) by hand and this solved problem for me:
l2tp_standard:
...
set l2tp self 192.168.0.1
Now both L2TP sessions from BO to HO are established. Sockstat shows mpd is listening on LAN IP only.

Link to my question in pfSense's forum:
https://forum.pfsense.org/index.php?topic=95908.0

P.S. Another desire to be able to setup two or more independent L2TP servers (as we can do for OpenVPN). It'll make easier to setup interfaces costs for OSPF.