As you know, the cross-domain problem is a tough one. We have a few workarounds that we have implemented, but all of them have been on the content side...below is a pdf to several solutions to the cross domain problem from the ADL site.
Some versions of the SCORM Engine implement the "Run-Time Service on Content Server" solution. The SCORM Driver can be upgraded to implement an updated version of the "SCO URL Callback Technique".