As you can see on the prev task log its not reused, clean backup. And you can see the interface usage too.
Previous manifest does not contain an archive called 'test.pxar.didx', skipping download..
test.pxar: had to backup 1 GiB of 1 GiB (compressed 1 GiB) in 10.38s
Ofc I do the new test file...