Nope. See here. clear lemmygrad magazine and we can see and interact just fine. I’ve also seen lemmygrad users comment here and there. Their stuff doesn’t pop up often for me, but it’s clear we’re federated.

Edit: here’s the lemmygrad feed you can see that it has stuff from lemmygrad users a mere 10 hours ago. and afaik neither way defederated since then.