That will still only give you one workpiece on the fixture, so you then have to get clever for step 2.
2. Sprut's toolpaths have an option to create linear or circular arrays of each toolpath, found under Transformation in the toolpath settings. Since you know the spacing between parts in your fixture, you can just program a single part and array each toolpath. That's a lot quicker than trying to chain and select faces on each part on the fixture.