Should it use tnid or nid in the views relationship

In using the Flag module in a multilingual site we are encountering the foll. issue: the goal is to show translated flagged content if available or default flagged content if not available. In the query generated by views we find that nid is used to do the match with content_id. For our purposes tnid would work better.

So instead of:

SELECT node.nid AS nid,
   node.language AS node_language,
   node_weight.sticky AS node_weight_sticky
 FROM node node 
 INNER JOIN flag_content flag_content_node ON node.nid = flag_content_node.content_id AND flag_content_node.fid = 6

we would want:

SELECT node.nid AS nid,
   node.language AS node_language,
   node_weight.sticky AS node_weight_sticky
 FROM node node 
 INNER JOIN flag_content flag_content_node ON node.tnid = flag_content_node.content_id AND flag_content_node.fid = 6

What is the best way of doing this in Flag or Views?