This does seem the appropriate forum–they eventually wander over to Github issues and are assigned. We really would be grateful for your assistance in fixing bugs. And it is not a requirement that you do so.
It is indeed something we can improve. When launching the new site last year, we took a lot of time to make sure that the various social media formats produced sane results. So that’s a start; but we can definitely improve. I am not 100% sure how all this works, but I understand that at least in some cases we can ensure we provide context-relevant metadata. I’ll make a ticket for it.
Indeed, it is a very difficult technical question. I worked on this for a long time but it was very difficult to get the system to work with the relatively new Google Polymer Webcomponents, especially also with different browsers. Firefox has in the mean time updated it’s software so these webcomponents can be rendered better.
But all this was a year ago and technology moves ahead at a fast pace. So it might indeed be time to revisit this issue and see what can be done.