Hello @Philip Mabon and welcome to Microsoft Q&A.
I think the SHIR should be smart enough to avoid the transfer, given you select it for that dataset pair. To be sure I propose the following test. Tell me whether you think this test is good enough.
I will install SHIR on my computer, and create 2 datasets for different locations on my computer file system. I make a file of a significant, known size.
I will schedule a run, then turn off all my other applications and watch the traffic via the Task Manager or similar tool.
I expect a small bit of traffic to fetch instructions for the task. The traffic should be much less than the file size.
If the traffic is less than file size, and copy succeeds, then SHIR is smart enough not to upload / download.
If traffic is close to file size, and copy succeeds, then SHIR is not smart enough.
Sound good?
Update: I have confirmed the outbound network b/s is less than the disk write b/s to the best of my ability.