it's a good question, I think we don't have an answer yet for that.
The way you are thinking about doing it, indeed will proabably not work because of the action value parameter in the link that tells if the URL contains a window state or not.
I think that the solution lies in the portlet bridge.
are you referring to the org.apache.portals.bridges? We are already using the portlet filter provided by this.
alternatively, how would I create a link in one portlet to launch into another portlet that is maximized?