Neither one of those links were to 5.6 specific IP sec implementation (or even had links to 5.6 docs).
eSmith 5.5 uses Freeswan 1.97-07 and 5.6 uses Freeswan 1.98b
I have been working on the same thing this morning as I have added another esmith box and have 5.6 on it.
It doesn't look pretty, but maybe I could package it up when I am done.
good luck.