I was in Cheshunt on Friday and I decided to test whether
my Freedom Pass would open the gates. It didn't. A station
attendant saw that I had a Freedom Pass and opened the
gates for me, saying "Platform three, my love," the platform
used only by LO trains via Seven Sisters and Edmonton Green.

In other words, you gentlemen are correct. The Freedom Pass
is valid as far as Cheshunt only if one travels on the LO service.