Hey moetiker,
I know this topic is quite old but just for clarification and to close this topic.
Right now there are two zimlets out there:
The development of the haiwen zimlet has stopped in 2016.
But we asked Barry de Graaff to enhance the Zimbra-Community zimlet to support also seafile and he did it. Here is the link to the annoucement: New Zimbra plugin for Seafile Server.
If there is any feature inside the haiwen zimlet that is not yet support by the new one we will make sure that this feature will be merged.
Best regards
Christoph