For anybody who missed this well-hidden new feature, you can turn on links from Dreamwidth to the crossposts. To do so you'll need to go to the "Other Sites" tab of your Settings, click on "Change" on the site you want linked to, and turn on the checkbox for "Display cross post links".
I don't know why it's buried so deep, but there you go.
Looks like it only affects posts made after changing the setting. I'm not sure if there's a way to go back and retroactively add it to everything else.
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