@ta180m How does this violate AP spec if the type is not supported by the remote server? (I don't remember seeing anything about this in spec, but I'd like to see, so things can be fixed)

Support for those types could be added in Pleroma, though, depending on what the issue is.

ActivityStreams supports using an array on `type` to specify that an activity may be multiple types (using e.g. the supported base activity type first, and the extended type second), which would help servers in understanding activities for types they do not understand.