Since there's a mod kind enough to spend time answer questions, could I ask a couple of things as well?

Is there a way to see whether mander has defederated from other communities?

I understand that defederated community content won't show when I'm signed in to a community that is not in federation with said communities. But is it still possible to make posts to communities defederated from my home account (in this case mander)?

This is a known issue that affects Lemmy: https://github.com/LemmyNet/lemmy-ui/issues/1315 I think that the message appears but that the subscription does go through. But correct me if I am wrong, I am interested.

Regarding the pending subscription message, I have read in a couple of lemmy guides that this is the case. I can confirm it myself, I have a few pending subscriptions but I do see the content of these communities.