I don’t know if you’re aware of this, but every page on HMF contains content references that are not secure. It seems the forum makes use of Schema.org to manage the structured content of the pages. However, throughout the page source all the references are to http://schema.org and not https://scheme.org. I’m not familiar with Discourse forum software, so it might be an inherent issue with the Discourse software that simply embeds it that way or it is something entered incorrectly when the forum was setup.
I realise in the grand scheme of things it’s a small matter, but I thought I’d mention it in case it’s something that has been bothering whoever manages the site (@wincenworks or one of the mods?) and they wanted to resolve it.