I think the really important question is… why do you even need a footer?
What is so important to put into the footer that you’d break the entire Discourse system, which is designed around infinite scrolling?
There’s really no great answer to that question, as About or Contact or other links can be put into a variety of other places, including a site-specific custom header at the top. I think trying to jury-rig old and outdated concepts into this new forum just doesn’t work.
Discourse is about discussion, and how to make that better. Nothing about a footer made a discussion better at any point for anybody.