Looking in to the BES.XSD schema, the “SourceFixletAction” type does not allow for overriding the Relevance or ActionScript from the source fixlet/source baseline. I suspect this is to allow for enforcing the “Custom Content” operator right - as overriding the ActionScript or Relevance would likely count as “Custom Content”, I think an operator who is granted rights to Take Action without having Custom Content can probably only send SourcedFixletAction actions.
What I think needs to happen in this case is to build the full MultipleActionGroup XML. It will end up looking the same as an exported Action from the baseline, with the complication that exporting the Action strips out the Targeting and SourceFixletID nodes. You’ll need to add those back in, they appear after
<SettingsLocks> per the schema for MultipleActionGroup. The Baseline’s source site can be defined by GatherURL, SiteID, or Site Name. Here’s an example (using SiteName):
<!-- <GatherURL>http://BES-Dev-Root:52311/cgi-bin/bfgather.exe/CustomSite_Production</GatherURL> -->
<!-- <SiteID></SiteID> -->