An IFTTT Channel would be a nice Pro feature.
As an example - it'd be great to be able to set up a recipe so that when I log a new movie it's cover art and my review are piped through to my Day One journal automatically. I'm sure there are many other uses it could be put to.
You can use the RSS feed on your profile page with IFTTT to auto-publish your new diary entries and lists. Search IFTTT for Letterboxd recipes to find examples.
I'll give it a go, ta.