defining the semantics of lists

I’m aware that the topic of lists in RDF can ingnite lively debate nearly as much as blank nodes so my apologies in advance. I have a very specific question and I don’t intend to discuss the use of lists in OWL, syntactic sugar in Turtle, querying in SPARQL or historic details about how some decisions came to be (although I do find all that very interesting, but another time...).

Lists from the RDF container vocabulary - rdf:Seq, rdf:Bag and rdf:Alt - can’t be closed whereas lists from the collection vocabulary - rdf:List - are always closed. Collections, in constrast to containers, are popularly considered to "have semantics" because of this closing characteristic. 
The excruciatingly exact Lisp-style modelling of rdf:Lists through rdf:first/rest/nil properties does indeed leave no room for misunderstanding about the listiness and closedness of an rdf:List.
What level of semantics could be provided for containers by explicitly defining either a closed container, e.g. rdfx:ClosedSeq, or an appropriate property, e.g. rdfx:hasLength, that implicitly closes a container? 

I reckon that semantics introduced per definition are always somewhat weaker than semantics that emenate naturally and unmistakably from a datastructure itself. However collections have a lot of disadvantages (that I promised above not to discuss) and I wonder how workable the semantics provided by defining an rdfx:ClosedSeq class or an rdfx:hasLength property would be. Would they be able to take some load, none at all, not enough, or almost the same as collections?

Thomas