The mediaType property is missing in the FEP-e232 link. Its value should be application/ld+json; profile="https://www.w3.org/ns/activitystreams";: https://codeberg.org/fediverse/fep/src/branch/main/fep/e232/fep-e232.md#object-links
You might also want to add quoteUrl property, because some platforms don't support FEP-e232 links yet (e.g. Misskey).
