I've been investigating various slow threads on the Org over the past few weeks. It seems that a mod I introduced to ensure all images are served over https (so we get the green padlock) was introducing a substantial delay in page loading times, particularly with older threads.

If people could check their signatures and other images and ensure that are served over https that would be a great help. Often this just means changing http to https in the link. This is particularly true of images that are no longer available (eg the hosting server is no longer online). It's possible I can modify certain links automatically, particularly to major hosting sites.