The SCP plugin doesn't seem to work correctly with the promoted builds plugin. I'm not sure which plugin the bug is in, but assigning it to SCP for now.
Steps to reproduce:
Create a new free-style project.
Add Post-build Action "Publish artifacts to SCP Repository", add a source filename
Select "Promote builds when..." and add an SCP action (with a source filename for clarity).
Save the changes and click to look at the project configuration again.
Both SCP tasks now incorrectly have both filenames, and clicking Save again will cause the filenames to be repeatedly duplicated.
It's also not possible to save different SCP sites for the promoted build and the post-build action.
To my untrained eye it looks like for Promoted Builds a separate DB entry isn't being created, and instead both the SCP tasks are clobbering the same field.